arm64: xilinx: dts: Add dma properties to fix dtbs_check warnings

Update dma name and add #dma-cells properties to fix dtbs_check
warnings.

Signed-off-by: Shravya Kumbham <shravya.kumbham@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/fedbf83fd5c682b4d61905d2cb790d33c2f079d6.1642160644.git.michal.simek@xilinx.com