Nucleo F303RE: Comment out CONFIG_APPS_DIR

Nucleo F303RE: Add serialrx configuration

Refresh all configurations that have SMARTFS enabled.  They should have MKSMARTFS enabled for backward compatibility.

added unique id implementation for f4discovery

added unique id implementation for nucleo-f303re

In protected build, need to specify CPU configuration on GCC command line or we get the wrong libgcc

Added a lower-half timer driver for stm32 which is compatible with the upper-half driver located at /drivers/timers/timer.c

Added a lower-half timer driver for stm32 which is compatible with the upper-half driver located at /drivers/timers/timer.c

configs/stm32f429i-disco/src/stm32_nsh.c file calculated partition boundries based on page block sizes but mtd_partition is expecting calculations based on erase block size.  From Alan Carvalho de Assis.

Nucleo F303RE: Move C++ initialization from configs to apps/platform