ASoC: dt-bindings: cros_ec_codec: add SHM bindings

- Add "reg" for binding to shared memory exposed by EC.
- Add "memory-region" for binding to memory region shared by AP.
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20191017213539.06.I0df85fe54162426e31f60a589d9b461c65df2faa@changeidSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/google,cros-ec-codec.txt

@@ -10,8 +10,26 @@ Required properties:
 - compatible: Must contain "google,cros-ec-codec"
 - #sound-dai-cells: Should be 1. The cell specifies number of DAIs.
 
+Optional properties:
+- reg: Pysical base address and length of shared memory region from EC.
+       It contains 3 unsigned 32-bit integer.  The first 2 integers
+       combine to become an unsigned 64-bit physical address.  The last
+       one integer is length of the shared memory.
+- memory-region: Shared memory region to EC.  A "shared-dma-pool".  See
+                 ../reserved-memory/reserved-memory.txt for details.
+
 Example:
 
+{
+	...
+
+	reserved_mem: reserved_mem {
+		compatible = "shared-dma-pool";
+		reg = <0 0x52800000 0 0x100000>;
+		no-map;
+	};
+}
+
 cros-ec@0 {
 	compatible = "google,cros-ec-spi";
 
@@ -20,5 +38,7 @@ cros-ec@0 {
 	cros_ec_codec: ec-codec {
 		compatible = "google,cros-ec-codec";
 		#sound-dai-cells = <1>;
+		reg = <0x0 0x10500000 0x80000>;
+		memory-region = <&reserved_mem>;
 	};
 };