driver on STM32F4Discovery rev. C boards and attach the associated interrupt callback.

Added the argument parameter (FAR void *arg) to the interrupt handler provided by the LIS3DSH
driver to fit the definition for ISRs in xcpt_t.

Changed the check for working queue availability in lis3dsh interrupt handler to use work_available()
and not crash in case of an overrun.

stm32x i2c fixes

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

  Injecting data errors would cause the driver to
  continually reenter the isr with BERR an RxNE.
  This fix allows the error to be cleared and
  propagated to the waiting task.

  Injecting data errors would cause the driver to
  continually reenter the isr with BERR an RxNE.
  This fix allows the error to be cleared and
  propagated to the waiting task.

Rename CONFIG_AUDIO_DEVICES to CONFIG_DRIVERS_AUDIO to conform better to the evolving configuration naming standard.

Rename CONFIG_VIDEO_DEVICES to CONFIG_DRIVERS_VIDEO to conform better to the evolving configuration naming standard.

sim/configs/fb:  Add a configuration for non-graphical testing of the frambuffer character driver using apps/example/fb

drivers/video/fb.c and include/nuttx/video.fb.h:  Some improvements and fixes from early testing sith the sim/fb cnofiguration.

latest updates on lc823450

* arch/arm/src/lc823450: Conform to the NuttX coding style

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

* arch/arm/src/lc823450: Merge the latest fix in lc823450_rtc.c

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

* arch/arm/src/lc823450: Add ADC driver

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

* arch/arm/src/lc823450: Add watchdog driver

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

* configs/lc823450-xgevk: Enable ADC and watchdog driver

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

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

drivers/video/fb.c:  Add support for LCD drivers that use a simulated framebuffer and must receive explicit notification when there is an update to a region in the framebuffer.

    drivers/video/fb.c:  Framebuffer driver is code complete but as of yet untested.
    drivers/video/fb.c:  Add framebuffer character device.  This is basically only the framework for the driver; a lot of logic is still missing.

Master

* smps.c: fix error messages

* stm32f33xxx_hrtim.h: fix definition

* stm32_hrtim: fix pclk calculation

* stm32_hrtim.c: cosmetics

* smps.h: cosmetics

* add upper-half driver for high power LED driver (powerled)

* stm32f334-disco: beginning of lower half driver for high power LED (powerled)

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

:Remove CONFIG_NET_6LOWPAN_FRAMELEN.  In this case where multiple radios are support3d, this may not be a constant.  6LoWPAN now always queries the driver to get the maximum frame length.

6LoWPAN: Remove the option to disable fragmentation support.  Two reasons:  (1) First fragementation is always required becaues IPv6 requires an MTU of 1280 bytes.  The is no application use case that can work without fragmentation support.  And (2) it greatly reduces the complexity of the code.

6LoWPAN/Radio:  Rename radio property sp_pktlen to sp_framelen.  Add 6LoWPAN utility to get the max frame length (not yet hooked in)

6LoWPAN: I believe, based on RFC review, that with the last multicast change, the NuttX 6LoWPAN is now compliant with RFC 6282.

Update/fix last commit:  On some STM32's, the CSR regiser is 18 vs. 16 bits wide.  Need to use 32-bit register accesses.

sem_open() should return SEM_FAILED on any failures.  This is change change in the POSIX specification since the original sem_open() was written so many years ago.