ARM: dts: msm: Add glink channel documentation

Add glink channel documentation used for communication between
monaco and slate.

Change-Id: Ie092dfb7da3402a2b821c9cbe0bfa35d2d7af309
Signed-off-by: Akshay Gola <quic_agola@quicinc.com>

bindings/soc/qcom/qcom,slate_touch_rpmsg.yaml

@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/qcom/qcom,slate_touch_rpmsg.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: slatetouch-rpmsg GLINK communication
+
+maintainers:
+  - Akshay Gola <quic_agola@quicinc.com>
+
+description: |
+  slatetouch-rpmsg is used to communicate with Slate over Glink
+  to configure the touch events slatetouch-rpmsg send commands over glink to
+  send configure, enable/disable touch to Slate
+
+properties:
+  compatible:
+    const: "qcom,slatetouch-rpmsg"
+    description: must be "qcom,slatetouch-rpmsg"
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    qcom,slatetouch-rpmsg {
+        compatible = "qcom,slatetouch-rpmsg";
+    };