ARM: dts: stm32: Rename eth@N to ethernet@N on DHCOM SoM

Fix the following dtbs_check warning:
eth@1,0: $nodename:0: 'eth@1,0' does not match '^ethernet(@.*)?$'

Signed-off-by: Marek Vasut <[e-mail]>
Cc: Alexandre Torgue <[e-mail]>
Cc: Patrice Chotard <[e-mail]>
Cc: Patrick Delaunay <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
To: [e-mail]
Signed-off-by: Alexandre Torgue <[e-mail]>

arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi

···
 	pinctrl-1 = <&fmc_sleep_pins_b>;
 	status = "okay";
 
-	ksz8851: ks8851mll@1,0 {
+	ksz8851: ethernet@1,0 {
 		compatible = "micrel,ks8851-mll";
 		reg = <1 0x0 0x2>, <1 0x2 0x20000>;
 		interrupt-parent = <&gpioc>;