SAMD External Interrupt Controller (EIC) support

* SAMD External Interrupt Controller (EIC) support

* removed comment

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

SAMDL fix g_spi2ops and g_spi2dev using incorrect values

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

arch/arm/src/samdl: In sam_spibus_initialize(), the pinmux configuration was smashing the previous CTRLA register configuration. There are also some typos in samd_spi.h

lc823450 dvfs

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

Apply the latest Kconfig to all configurations.
Enable DVFS in audio and rndis. Add telnet character mode to rndis.

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

Add notes on DVFS (Dynamic Voltage and Frequencey Scaling)

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

This version only supports manual mode and Vdd1 is fixed to 1.2V.

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

drivers/net: Add support for telnet character mode

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

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

    configs/flipnclick-pic32mz:  Switch the serial console to UART4.  Clean up some minor issues the LED options.
    configs/flipnclick-pic32mz:  Add support for two on-board buttons:  T1 and T2.
    configs/flipnclick-pic32mz:  Adds basic board support for the Mikroe Flip&Click PIC32MZ board.  Initial commit is just the configs/pic32mz-starterkit with some name chanages.

    arch/mips/src/pic32mz:  Commits the basic architecture port for the PIC32MZEF.
    arch/mips/src/pic32mz:  Begin adding PIC32MZEF files. Initial commit are simply PIC32MZEC files with name changes.
    arch/mips/include/pic32mz:  Add support for the PIC32MZEF family.

    configs/flipnclick-sam3x:  Add support for the 4 user-controllable LEDs on the board.
    configs/flipnclick-sam3x:  Add board support for the Mikroe Flip&Click SAM3X.
    configs/arduino-due:  Update this old configuration so that it is structured a little more like recent board support.

    fs/nxffs:  Giving up on truncate() support in NXFFS for now.  There is too much that has to be done to make that work.
    configs/sim:  Add support for testing NXFFS.

    fs/smartfs:  Add logic needed to ftruncate to shrink a file to any arbitrary size.
    fs/smartfs:  Repartition some functionality to better fit in new ftruncate features.

FAT. Effectively handles the situation when a new file position is within the current sector.

* Find begin of the next token

* EOL

* revert

* Accelerates the work of the FS with a multitude of operations to write small pieces of data within the current sector.

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

net/route:  Fix a couple of compile-related issues that have crept in sense the last time the file-based routing table was used.

Squashed commit of the following:

    fs/fat:  Resolves issues with truncating the cluster chain when shrinking files via ftruncate().
    fs/fat:  First cut at implementation file shrinkage logic needed to support ftruncate().  Certainly shrinks the file size but it does not appear to correctly disconnect the cluster chains.
    fs/fat:  Restructure some functions in files to better support forthcoming file shrinkage logic.  Put framework for file shrinkage in place.  That logic is incomplete on initial commit.

fs/nxffs: truncate method is implementated in a separate file and should have been in a previous commit.

    fs/nxffs:  Add partial implementation of the truncate method:  It extend files, but cannot yet shrink them.
    fs/smartfs:  Add partial implementation of the truncate method:  It extend files, but cannot yet shrink them.
    fs/fat:  Add partial implementation of the truncate method:  It extend files, but no yet shrink them.
    fs/nfs:  Add support for the truncate method to the NFS file system.

    fs: Add truncate() support for userfs
    fs/unionfs:  Add truncate() support to the unionfs
    fs/tmpfs:  Add ftruncate() support to tmpfs
    syscall/: Add system call support for ftruncate()
    net/route:  Adding ftruncate() support eliminates an issue in file-based routing table management.
    fs:  Add basic framework to support truncate() and ftruncate().  The infrastructure is complete.  Now, however, the actual implementation of ftruncate() will have to be done for each file system.