ARM: dts: r9a06g032: Correct the GIC DT node name

Harmless mistake, but it's incorrect. The DT spec provides recommendations
for the node names:
"The name of a node should be somewhat generic, reflecting the function
of the device and not its precise programming model. If appropriate, the
name should be one of the following choices:
...
interrupt-controller"
Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r9a06g032.dtsi

@@ -173,7 +173,7 @@ pinctrl: pin-controller@40067000 {
 			status = "okay";
 		};
 
-		gic: gic@44101000 {
+		gic: interrupt-controller@44101000 {
 			compatible = "arm,cortex-a7-gic", "arm,gic-400";
 			interrupt-controller;
 			#interrupt-cells = <3>;