dt-bindings: dmaengine: at_xdmac: add compatible with microchip,sam9x7

Add compatible for sam9x7.

Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230728102451.265869-1-varshini.rajendran@microchip.com


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