arm64: dts: r8a7795: update PFC node name to pin-controller

The device trees for Renesas SoCs use either pfc or pin-controller as the
node name for the PFC device. This patch is intended to take a step towards
unifying the node name used as pin-controller which appears to be the more
generic of the two and thus more in keeping with the DT specs.

My analysis is that this is a user-visible change to the extent that kernel
logs, and sysfs entries change from e6060000.pfc and pfc@e6060000 to
e6060000.pin-controller and pin-controller@e6060000.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/r8a7795.dtsi

@@ -398,7 +398,7 @@ sysc: system-controller@e6180000 {
 			#power-domain-cells = <1>;
 		};
 
-		pfc: pfc@e6060000 {
+		pfc: pin-controller@e6060000 {
 			compatible = "renesas,pfc-r8a7795";
 			reg = <0 0xe6060000 0 0x50c>;
 		};