KL25 DMA, DMAMUX, LLWU, ADC, LPTMR, TSI, MCG regs.

Added peripheral structures and register constants for KL25Z4 MCU
peripherals: DMA, DMAMUX, LLWU, ADC, LPTMR, TSI, and MCG.
Merge pull request #4 from cdbennett/kl25-registers-dma-tsi-mcg-etc

KL25 DMA, DMAMUX, LLWU, ADC, LPTMR, TSI, MCG regs.