dt-bindings: Add snapshot of virtio-mem documentation

Snapshot the virtio-mem documentation from
qcom-6.1 commit a495f33fe39b ("ARM: dts: msm: Add ipcc_mproc_ns1 for
cliffs TUIVM").

Change-Id: I86b8c4c06d7c5c9ab2110b31f673f7414c43c66b
Signed-off-by: Patrick Daly <quic_pdaly@quicinc.com>

bindings/virtio/qcom,virtio-mem.yaml

@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/soc/qcom/qcom,secure-buffer.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Qualcomm Technologies, Inc. Virtio-Mem bindings
+
+description: |
+  QTI virtio mem driver supports Guest initiated memory hotplug operations
+  which transfer memory from Host to Guest.
+
+properties:
+  compatible:
+    items:
+      - const: qcom,virtio-mem
+
+  qcom,block-size:
+    description:
+      Minimum transfer size in bytes. Should be multiple of PAGE_SIZE.
+
+  qcom,max-size:
+    $ref: '/schemas/types.yaml#/definitions/uint64'
+    description: |
+      Maximum amount of hotpluggable memory this device supports.
+
+  qcom,ipa-range:
+    $ref: '/schemas/types.yaml#/definitions/uint64-array'
+    description: |
+      An inclusive range describing what address range the hypervisor
+      is allowed to choose when adding hotpluggable memory for this
+      device.
+
+  qcom,memory-encryption:
+    type: boolean
+    description: |
+      Indicates that virtio-mem should only accept memory which has at least
+      the same level of encryption as the base kernel.
+
+required:
+  - compatible
+  - qcom,size
+  - qcom,ipa-range
+  - qcom,block-size
+
+example:
+	virtio_mem_device@0x60000000 {
+		compatible = "qcom,virtio-mem";
+		qcom,block_size = <0x400000>;
+		qcom,size = <0x0 0x10000000>;
+		qcom,ipa-range = <0x0 0x0 0xf 0xffffffff>;
+	};