dt-bindings: dma: Rewrite ST-Ericsson DMA40 to YAML

This rewrites the ST-Ericsson DMA40 bindings in YAML.

Cc: Lee Jones <lee.jones@linaro.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220527215508.622374-1-linus.walleij@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>