Reverted MPU6000_BUS_I2C_INTERNAL1 back to MPU6000_BUS_I2C_INTERNAL
  Ony SPI has multiple device

  1) Ensure if CONFIG_SERIAL_DMA is set that cdcacm uart_ops is initalized
     with correct functions in correct slots.
     This was detected only with PX4 build flags
  2) C&P error from F7 would prevent CONFIG_STM32_SERIALBRK_BSDCOMPAT ifdefed
     code from being included.

   Incomplete changes to startup script for FMUv5.
   See "Place holder Need" in ROMFS/px4fmu_common/init.d/rc.sensors

  Fixes https://github.com/PX4/Firmware/issues/5710

  This is the fixes https://github.com/PX4/Firmware/issues/5710
  by adding 2 concepts.

  1) Allowing a board to define BOARD_HAS_SHARED_PWM_TIMERS
     in this case the io_timeris will be initalized as the
     led_pwm_timers  - there is an assumptionm that the
     number of io_timers == the number of led_pwm timers

  2) Allowing a board to define BOARD_LED_PWM_RATE
     To set an alternate frequency

  Future expansion will require:
  1) The ability to have a config with both the I2C RGB LED and
     PWM RGB LED drivers loaded.
  2) The higher level driver to create  multiple instances of the
     /dev/rgbld, to support internal and  external User facing
     RGB LED as supported in FMUv5

  Removed dead code and magic numbers
  Defined the RGB LED to support 2 timers

   Set inital State to ON
   Add interface macro.

Nuttx added FIONSPACE and fixed FIONWRITE: had retuned the space and should have returned enqueued count