corstone1000: add fwu-metadata store info

Add fwu-mdata node and handle for the reference
nvmxip-qspi.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
diff --git a/arch/arm/dts/corstone1000.dtsi b/arch/arm/dts/corstone1000.dtsi
index 533dfdf..1e0ec07 100644
--- a/arch/arm/dts/corstone1000.dtsi
+++ b/arch/arm/dts/corstone1000.dtsi
@@ -38,7 +38,7 @@
 		reg = <0x88200000 0x77e00000>;
 	};
 
-	nvmxip-qspi@08000000 {
+	nvmxip: nvmxip-qspi@08000000 {
 		compatible = "nvmxip,qspi";
 		reg = <0x08000000 0x2000000>;
 		lba_shift = <9>;
@@ -106,6 +106,11 @@
 		method = "smc";
 	};
 
+	fwu-mdata {
+		compatible = "u-boot,fwu-mdata-gpt";
+		fwu-mdata-store = <&nvmxip>;
+	};
+
 	soc {
 		compatible = "simple-bus";
 		#address-cells = <1>;