arm64: s32g2: Pass unit name to soc node

Pass unit name to soc node to fix the following W=1 build warning:

arch/arm64/boot/dts/freescale/s32g2.dtsi:82.6-123.4: Warning (unit_address_vs_reg): /soc: node has a reg or ranges property, but no unit name
Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Chester Lin <clin@suse.com>
Signed-off-by: Chester Lin <clin@suse.com>
Link: https://lore.kernel.org/r/20220514143505.1554813-1-festevam@gmail.com

arch/arm64/boot/dts/freescale/s32g2.dtsi

@@ -79,7 +79,7 @@ psci {
 		};
 	};
 
-	soc {
+	soc@0 {
 		compatible = "simple-bus";
 		#address-cells = <1>;
 		#size-cells = <1>;