dt-bindings: Add dt bindings for memory dump

Add device tree binding documents for memory dump driver.

Change-Id: Id8cd38a723559188bbabe60f82df3a111101ed34

bindings/arm/msm/msm_memory_dump.txt

@@ -0,0 +1,32 @@
+Qualcomm Technologies Inc. memory dump driver
+
+QTI memory dump driver allows various client subsystems to register and
+allocate respective dump regions. At the time of deadlocks or cpu hangs
+these dump regions are captured to give a snapshot of the system at the
+time of the crash.
+
+Required properties:
+
+-compatible: "qcom,mem-dump"
+-memory-region: phandle to the CMA region. The size of the CMA region
+		should be greater than sum of size of all child nodes
+		to account for padding.
+
+If any child nodes exist the following property are required:
+
+-qcom,dump-size: The size of memory that needs to be allocated for the
+		 particular node.
+-qcom,dump-id: The ID within the data dump table where this entry needs
+	       to be added.
+
+Example:
+
+	mem_dump {
+		compatible = "qcom,mem-dump";
+		memory-region = <&dump_mem>;
+
+		rpmh_dump {
+			qcom,dump-size = <0x2000000>;
+			qcom,dump-id = <0xEC>;
+		};
+	};