patches: Drop drivers/dma/mmp_pdma.c patch

Upstream commit a50f7456f853 ("dma-mapping: Allow use of
DMA_BIT_MASK(64) in global scope") avoids the warning that this patch
was meant to hide. It is still in the dmaengine tree but it does not
need to be applied to our CI anymore.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Author: nathanchance