ARM: dts: silk: Name serial port pfc subnode after device name

Name the Pin Function Controller subnode for SCIF2 after its device
name, instead of using some arbitrary name that looks like a serial port
alias, but differs from the actual alias.

This avoids conflicts when enabling support for more serial ports later,
either here or in a DT overlay.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

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

@@ -129,7 +129,7 @@ &pfc {
 	pinctrl-0 = <&scif_clk_pins>;
 	pinctrl-names = "default";
 
-	scif2_pins: serial2 {
+	scif2_pins: scif2 {
 		groups = "scif2_data";
 		function = "scif2";
 	};