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: NMichal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-7000.dtsi

@@ -57,7 +57,7 @@
 		regulator-always-on;
 	};
 
-	amba {
+	amba: amba {
 		compatible = "simple-bus";
 		#address-cells = <1>;
 		#size-cells = <1>;

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";