dmaengine: jz4780: Add support for the MDMA and BDMA in the JZ4760(B)

The JZ4760 and JZ4760B SoCs have two regular DMA controllers with 6
channels each. They also have an extra DMA controller named MDMA
with only 2 channels, that only supports memcpy operations, and one
named BDMA with only 3 channels, that is mostly used for transfers
between memories and the BCH controller.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20211206174259.68133-5-paul@crapouillou.net


Signed-off-by: Vinod Koul <vkoul@kernel.org>