ARM: dts: msm: gunyah: Add gh-msgq-test binding

Add gh-msgq-test binding description and requirements which include
compatible, label and optional properties.

Change-Id: Ie894c1ca2179c9fed9b066893de03eff60749c81
Signed-off-by: Po-Jung Lai <quic_pojulai@quicinc.com>

bindings/soc/qcom/qcom,gh-msg-test.yaml

@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/qcom/qcom,gh-dbl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: QCT Gunyah Hypervisor Message Queue Test Driver
+
+maintainers:
+  - Murali Nalajala <quic_mnalajal@quicinc.com>
+  - Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com>
+  - Po-Jung Lai <quic_pojulai@quicinc.com>
+
+description: |
+  The Gunyah Hypervisor Test Driver is used to validate gunyah hypervisor
+  functionality. It includes test nodes for transferring gunyah message
+  queue between VMs.
+
+properties:
+  compatible:
+    const: qcom,gh-msgq-test
+
+examples:
+  - |
+    Master:
+    qcom,test-msgq {
+      compatible = "qcom,gh-msgq-test";
+      gunyah-label = <4>;
+      qcom,primary;
+    };
+    Client:
+    qcom,test-msgq {
+      compatible = "qcom,gh-msgq-test";
+      gunyah-label = <4>;
+      affinity = <0>;
+    };