net/udp:  Correct an error introduce in recent fixes for UDP connected sockets.  The interaction between psock_udp_send() and psock_udp_sendto() was perverse:  It should always pass a NULL destinatino address.

This commit adds basic architectural support for the OpenRISK mor1kx architecture.  The initial commit was verified on a Qemu simulation but is otherwise untested.

Squashed commit of the following:

Author: Gregory Nutt <gnutt@nuttx.org>
    Update README.
    configs/or1k:  Should include header file file where exported functin is prototyped.
    arch/or1k/src:  Eliminate some warnings.
    arch/or1k:  Complete review
    Fix some recently introduced build issues
    configs/or1k/nsh:  Convert to proper, compressed defconfig file.
    Another README update.
    Update README
    configs/or1k:  Updates from initial review.
    Update README.

Author: Matt Thompson <matt@extent3d.com>

    or1k: Added configurable CPU frequency to Kconfig. Calculate tick timer match period based on configured frequency.
    OpenRISC: Enable instruction and data cache
    OpenRISC: Initial support.

configs/photon:  Refresh all configurations.  configurations the use the SDIO card interface must support CONFIG_STM32_SDIO_CARD.

drivers/wiresless/ieee80211:  Correct some initialization problems with BCM43362 chip.  Adds BCM43428 support.  arch/arm/src: Add support for SDIO card to SDIO driver.

Squashed commit of the following:

Author: Gregory Nutt <gnutt@nuttx.org>
    include/nuttx/wireless/ieee80211:  Cosmetic, coding standard changes from review of last merge.
    drivers/wireless/ieee80211:  Cosmetic, coding standard changes from review of last merge.
    configs/photon:  Cosmetic, coding standard changes from review of last merge.
    arch/arm/src/stm32:  SDIO changes from last review:  Fix a few long lines and other coding standard issues; Make additions for SDIO card support dependent on a configuration option.

Author: hhuysqt <hyq9606@126.com>
    Return IEEE 802.11 MAC address just as ethernet does
    Modifyed bcmf_board_setup_oob_irq declaration
    Modified OOB ISR function types
    Add some logic according to WICED SDK
    Bug fixed: data_offset counts in 4-bytes
    Add BCM43438 logic for future developement
    Add tips on using telnet
    Use SDIO in-band interrupt instead of OOB interrupt, because Photon seems to unconnect the OOB interrupt line...
    add SDIO in-band interrupt logic

arch/arm/src/imxrt:  Minor reparitioning to account for the fact that the GPIO5 base address is not contiguous with the GPIO1-4 base addresses.

include/nuttx/wireless:  Add a setbaud() method to the HCI UART lower half interface that can be used to change the default BAUD selection.  arch/arm/src/stm32:  Implement the setbaud() method for the STM32 HCI UART.

net/udp:  Minor update from review of 091e3f73.  In connect(), AF_UNSPEC is used to disconnect UDP socket.  However, initial commit lacked logic to mark the socket as disconnected.

net/udp:  Fix several issues using connected UDP sockets:  sendto() should not accept and address.  Normally send() should be used instead.  recvfrom() is no longer necessary.  recvfrom() and poll() should not reset to accept any addresses but should, instead, only accept inputs and events from the connected remore peer.  On of these issues was noted by 李桂丁 <liguiding@pinecone.net>.  Changes were made as summarized here: http://www.masterraghu.com/subjects/np/introduction/unix_network_programming_v1.3/ch08lev1sec11.html

tools/configure.sh:  Fix last commit.  If gmake is not present, then 'which gmake' spews a lot of annoying error messages when configuring.  Best to pipe stderr to /dev/null so that we are blessedly unaware of the failures.

Add clang support to stm32f746g-disco board

Approved-by: Gregory Nutt <gnutt@nuttx.org>

drivers/1wire: add PM hooks and unlink support to sht21 sensor (allowing hot-swappable I2C bus from 1-wire converter)

* drivers/1wire: add PM hook to 1wire bus

* drivers/1wire/ds28e17.c: i2c instance must be zeroed

* drivers/sht21: add unlink support

    Unlike most other unlink implementations in NuttX drivers, this one
    does not allow any I2C operations after unlink, making it possible to
    deallocate the I2C bus.

Approved-by: Gregory Nutt <gnutt@nuttx.org>

configs/stm32f4discovery/hciuart:  Disable MMC/SD support.  That made it difficult to re-use the configuration without the base board.  MMC/SD support is not needed in that configuration anyway.

arch/arm/sc/lpc16xx:  Extends commit 456a258c:  Freeing endpoints should be set the same allocations as when endpoint was allocated.

configs:  Review all implementations of board_lcd_initialize().  The NuttX convention is that all internal functions that return errors as an 'int' must return a negated errno value on failure and a non-negative value on success.  Most were right but eight of them had cloned logic that returns 1 on success and zero on failure... both of which are interpreted as success by the caller since they are non-negative.

include/nuttx/wireless:  Add support for the rest of the IOCTL options needed to support apps/wireless/bluetooth/btsak.  This is only the IOCTL command definitions.  The IOCTL command implementation is still missing.