dt-bindings: dma: qcom,gpi: document the Milos GPI DMA Engine

Document the GPI DMA Engine on the Milos SoC.

Signed-off-by: Luca Weiss <[e-mail]>
Acked-by: Rob Herring (Arm) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

Documentation/devicetree/bindings/dma/qcom,gpi.yaml

···
           - qcom,sm6350-gpi-dma
       - items:
           - enum:
+              - qcom,milos-gpi-dma
               - qcom,qcm2290-gpi-dma
               - qcom,qcs8300-gpi-dma
               - qcom,qdu1000-gpi-dma