Adds support for the MSP430X's 12-bit ADC peripheral, as well as
reasonably complete testing of same.
Also includes fixes for several bugs and cleanup of the DMA peripheral,
which used ch calls rather than osal calls and was unclear about what
contexts its methods could be called from.
This port includes hal, pal, serial, and st drivers. It supports both
large and small model code and data for MSP430X-class CPUs. It has only
been tested on the EXP430FR5969 LaunchPad board.
Andrew Wygle