AP_Baro_MS5611_test: Add HAL specific code.
HAL_BOARD_ERLE: Fix the AP_BoardLED pins.
APM_Config: Modify the file according to the test platforms avail.
SPIDriver: BUS_SPEED selected individually
SPIDriver: Make the CS variables more readable
SPIDriver: Improve error handling
SPIDriver: Remove panic when invalid pin

When a invalid pin is passed as a parameter
the methods return without performing anything
insted of raising a panic.
RCOutput:add close(_fd) to some functions
RCOutput: change to directly accessing shared_mem of pru
Replace PRU1 firmware with a new one to support new way of controllong PRU PWM
RCOutput.cpp: Correct error inside read method
SPIDriver: Add FRAM support.
UARTDriver: UART-like TCP sockets impl. on AP_HAL_Linux
ArduPlane/config.h: Add the PXF hardware setup
SPIDriver: Fix FRAM code
Add initialising script and required overlays and firmware
RCOutput.cpp:change initial PWM values to 490Hz, 1000us
ArduCopter: Run the main loop at 100 Hz
AP_Motors_Time_test.pde: use hal.scheduler->micros instead of gettimeofday
AP_Motors_Time_test.pde: use hal.scheduler->micros instead of gettimeofday