dt-bindings: dma: ingenic: Add compatible strings for MDMA and BDMA

The JZ4760 and JZ4760B SoCs have two additional DMA controllers: the
MDMA, which only supports memcpy operations, and the BDMA which is
mostly used for transfer between memories and the BCH controller.
The JZ4770 also features the same BDMA as in the JZ4760B, but does not
seem to have a MDMA.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211206174259.68133-2-paul@crapouillou.net


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