ARM: shmobile: r8a7794: alt: Enable PFC DU for the VGA port

Tie in r8a7794 PFC DU support to the VGA port on the
r8a7794 ALT board.
Signed-off-by: NMagnus Damm <damm+renesas@opensource.se>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7794-alt.dts

@@ -80,6 +80,8 @@
 };
 
 &du {
+	pinctrl-0 = <&du_pins>;
+	pinctrl-names = "default";
 	status = "okay";
 
 	clocks = <&mstp7_clks R8A7794_CLK_DU0>,
@@ -101,6 +103,11 @@
 };
 
 &pfc {
+	du_pins: du {
+		renesas,groups = "du1_rgb666", "du1_sync", "du1_disp", "du1_dotclkout0";
+		renesas,function = "du";
+	};
+
 	scif2_pins: serial2 {
 		renesas,groups = "scif2_data";
 		renesas,function = "scif2";