dt-bindings: remoteproc: mediatek: Add optional memory-region to mtk,scp

The SCP co-processor can optionally be passed a reserved memory region
to use. Add this property in the dt-binding.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220511195452.871897-3-nfraprado@collabora.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Author: nfraprado

Documentation/devicetree/bindings/remoteproc/mtk,scp.yaml

@@ -54,6 +54,9 @@ properties:
       firmware search path containing the firmware image used when
       initializing SCP.
 
+  memory-region:
+    maxItems: 1
+
 required:
   - compatible
   - reg