drivers: dma: add DMA driver for NXP PXP engine

The NXP Pixel pipeline engine (PXP) is a 2D DMA engine capable of
accelerating display rotation, color space conversion, and limited
2D blending operations. This DMA driver only supports rotation of a
framebuffer, via a set of custom dma_slot values. Only DMA channel 0
is supported or utilized.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>