ARM: shmobile: r8a7778: Add pin control device to device tree

Add a pfc node to the r8a7778 device tree.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7778.dtsi

@@ -32,4 +32,9 @@
 		reg = <0xfe438000 0x1000>,
 		      <0xfe430000 0x100>;
 	};
+
+	pfc: pfc@fffc0000 {
+		compatible = "renesas,pfc-r8a7778";
+		reg = <0xfffc000 0x118>;
+	};
 };