ARM: dts: zynq: Add OCM node

Add OCM node for all zynq boards. OCM location
can changed but for all current boards this
is the location where OCM is.`

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-zc702.dts

@@ -50,6 +50,13 @@
 	};
 };
 
+&amba {
+	ocm: sram@fffc0000 {
+		compatible = "mmio-sram";
+		reg = <0xfffc0000 0x10000>;
+	};
+};
+
 &can0 {
 	status = "okay";
 	pinctrl-names = "default";