dmaengine: mmp_pdma: Add reset controller support

dmaengine: mmp_pdma: Add reset controller support

Add support to acquire and deassert an optional hardware reset controller
during mmp_pdma_probe(). It is optional because in Marvell devices
such as "marvell,pdma-1.0" the resets property is not a required
property. But in SpacemiT K1 PDMA, "spacemit,k1-pdma" as the dt
binding schema file stated, resets is required.

Signed-off-by: Guodong Xu <guodong@riscstar.com>
Link: https://lore.kernel.org/r/20250822-working_dma_0701_v2-v5-3-f5c0eda734cc@riscstar.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>