arm64: dts: renesas: s4sk: Fix ethernet0 alias

U-Boot uses "ethernet0", not "eth0".

While at it, fix nearby whitespace errors (TAB instead of space before
equal sign).

Fixes: 93be50c7 ("arm64: dts: renesas: Add R-Car S4 Starter Kit support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/2f62c29e4222387a95ebadc65ba90a0cdea9b78c.1712647914.git.geert+renesas@glider.be

arch/arm64/boot/dts/renesas/r8a779f4-s4sk.dts

@@ -14,9 +14,9 @@ / {
 	compatible = "renesas,s4sk", "renesas,r8a779f4", "renesas,r8a779f0";
 
 	aliases {
-		serial0	= &hscif0;
-		serial1	= &hscif1;
-		eth0	= &rswitch;
+		serial0 = &hscif0;
+		serial1 = &hscif1;
+		ethernet0 = &rswitch;
 	};
 
 	chosen {