ARM: zynq: Fix OCM mapping to be aligned with binding on zc702

The Linux commit f69629919942 ("dt-bindings: sram: Convert SRAM bindings to
json-schema") converted binding to yaml and some missing required
properties started to be reported. Align binding based on it.

The patch is fixing these warnings:
.../zynq-zc702.dt.yaml: sram@fffc0000: '#address-cells' is a required property
.../zynq-zc702.dt.yaml: sram@fffc0000: '#size-cells' is a required property
.../zynq-zc702.dt.yaml: sram@fffc0000: 'ranges' is a required property
>From schema: .../Documentation/devicetree/bindings/sram/sram.yaml

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/87c02786ccd8d7827827a9d95a8737bb300caeb0.1606397101.git.michal.simek@xilinx.com
diff --git a/arch/arm/dts/zynq-zc702.dts b/arch/arm/dts/zynq-zc702.dts
index e45eba3..4474f4b 100644
--- a/arch/arm/dts/zynq-zc702.dts
+++ b/arch/arm/dts/zynq-zc702.dts
@@ -68,6 +68,12 @@
 	ocm: sram@fffc0000 {
 		compatible = "mmio-sram";
 		reg = <0xfffc0000 0x10000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0 0xfffc0000 0x10000>;
+		ocm-sram@0 {
+			reg = <0x0 0x10000>;
+		};
 	};
 };