dt-bindings: media: st: dcmi: add DMA-MDMA chaining properties

Add properties update and new sram property necessary in order
to enable the DMA-MDMA chaining.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/devicetree/bindings/media/st,stm32-dcmi.yaml

@@ -27,11 +27,14 @@ properties:
       - const: mclk
 
   dmas:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
 
   dma-names:
     items:
       - const: tx
+      - const: mdma_tx
+    minItems: 1
 
   resets:
     maxItems: 1
@@ -40,6 +43,12 @@ properties:
     minItems: 1
     maxItems: 2
 
+  sram:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      phandle to a reserved SRAM region which is used as temporary
+      storage memory between DMA and MDMA engines.
+
   port:
     $ref: /schemas/graph.yaml#/$defs/port-base
     unevaluatedProperties: false