dt-bindings: dmaengine: dma-common: Fix the dma-channel-mask property

dt-bindings: dmaengine: dma-common: Fix the dma-channel-mask property

The commit 4ea88bbfdf93 ("dt-bindings: dmaengine: Add YAML schemas
for the generic DMA bindings") changed the property from
dma-channel-mask to dma-channel-masks. So, this patch fixes it.

Fixes: 4ea88bbfdf93 ("dt-bindings: dmaengine: Add YAML schemas for the generic DMA bindings")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1566988223-14657-1-git-send-email-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>