dt-bindings: dma: Add YAML schemas for dw-axi-dmac

YAML schemas Device Tree (DT) binding is the new format for DT to replace
the old format. Introduce YAML schemas DT binding for dw-axi-dmac and
remove the old version.

Signed-off-by: Sia Jee Heng <jee.heng.sia@intel.com>
Reviewed-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210125013255.25799-2-jee.heng.sia@intel.com


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