dt-bindings: dmaengine: xilinx_dma: Fix formatting and style

Trivial formatting(keep compatible string one per line, caps change etc).
It doesn't modify the content of the binding.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1571763622-29281-3-git-send-email-radhey.shyam.pandey@xilinx.com


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