ws281x driver using DMA SPI for msp430f5529

Here is some code to drive ws281x strips using DMA driven SPI for the msp430f5529. I hadn't seen any example code showing how to use DMA and SPI.  The example also provides some code that shows how to use inline asm that will work with both msp430-gcc and msp430-elf-gcc.

The code below was tested with a ws2811 strip and msp430-elf-gcc.

https://gist.github.com/RickKimball/9761b8f5a89d46a53939

-rick