Create tests for the MTrain board

[petersonev]

• Test Internal Hardware
  • Test GPIO
    • Test output (blink LED)
    • Test input (read button)
  • Test FMC
    • Connect to SDRAM
  • Test QSPI
    • Connect to FLASH
  • Test USB HS
    • Serial output over onboard USB
• Test External Hardware
  • Test SPI
  • Test I2C
  • Test timers
    • Test PWM
  • Test analog pins
    • Read analog in pin
    • Write to analog out pin
  • Test UART (priority low)
  • Test USART (priority low)
  • Test CAN (priority low)