ARM: dts: keystone-k2g: Add MSM RAM node

Add the RAM managed by the Multicore Shared Memory Controller (MSMC)
as a mmio-sram node. The 66AK2G SoCs have 1 MB of such memory. Any
specific MSM memory range needed by a software module ought to be
reserved using an appropriate child node.
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>

arch/arm/boot/dts/keystone-k2g.dtsi

@@ -77,6 +77,14 @@ soc {
 		ranges = <0x0 0x0 0x0 0xc0000000>;
 		dma-ranges = <0x80000000 0x8 0x00000000 0x80000000>;
 
+		msm_ram: msmram@0c000000 {
+			compatible = "mmio-sram";
+			reg = <0x0c000000 0x100000>;
+			ranges = <0x0 0x0c000000 0x100000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+		};
+
 		k2g_pinctrl: pinmux@02621000 {
 			compatible = "pinctrl-single";
 			reg = <0x02621000 0x410>;