ARC: dts: align SPI NOR node name with dtschema

The node names should be generic and SPI NOR dtschema expects "flash".
Signed-off-by: NKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: NVineet Gupta <vgupta@kernel.org>

arch/arc/boot/dts/hsdk.dts

@@ -275,7 +275,7 @@
 			cs-gpios = <&creg_gpio 0 GPIO_ACTIVE_LOW>,
 				   <&creg_gpio 1 GPIO_ACTIVE_LOW>;
 
-			spi-flash@0 {
+			flash@0 {
 				compatible = "sst26wf016b", "jedec,spi-nor";
 				reg = <0>;
 				#address-cells = <1>;