FX3 Cleanup tasks

There are several deficiencies in the FX3 firmware that should be resolved. At this point it probably no longer makes sense to make individual bugs for each, so instead I am list them here. I will begin burning down the list when I have time. If other people want to help, drop me a line and we can divide and conquer.

• FX3 firmware does not always check error codes from Cy API
• UART errors are not detected (framing/overflow)
• SPI errors are not detected (underflow/overflow)
• Once UART errors are detected, no way to report counters. Need to develop diagnostic data interface.
• It would be really nice to have logging support in the FX3 firmware.
• Fatal errors in the FX3 firmware result in lockup. Better to some how report to host problem occured.
• Implement suspend/resume (low priority)
• Add git rev to fx3 firmware build

Open questions:

• Order of shutting down EPs and DMAs. Should halt EP then DMA, or DMA then EP. Or either works?
• DMA for RF data is byte oriented. Should be symbol oriented?
• Unclear if endpoint halt feature is implemented correctly.