drivers: dma: Add Microchip XEC DMA driver

The Microchip XEC family of microcontrollers includes a
simple DMA block implementing multiple channels. DMA supports
memory to memory, memory to peripheral, and peripheral to
memory transfers. Peripheral support is limited by each
chip to I2C and SPI controllers. DMA hardware does not support
scatter-gather or linked transactions.

Signed-off-by: Jay Vasanth <jay.vasanth@microchip.com>