dts: cm5: Fix ethernet phy address

CM5 features the same Broadcom BCM54213PE phy for ethernet as present on
pi5, but with a different mdio address (0 instead of 1 on pi5).

Fix this and use correct mdio address 0. While at it set
interrupt_parent to rp1_gpio instead of gpio (which is an alias to the
former) as this is the handle already used in this block.

Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>

Author: nbuchwitz

arch/arm64/boot/dts/broadcom/bcm2712-rpi-cm5.dtsi

@@ -159,10 +159,10 @@ rp1_target: &pcie2 {
 	phy-reset-gpios = <&rp1_gpio 32 GPIO_ACTIVE_LOW>;
 	phy-reset-duration = <5>;
 
-	phy1: ethernet-phy@1 {
-		reg = <0x1>;
+	phy1: ethernet-phy@0 {
+		reg = <0x0>;
 		brcm,powerdown-enable;
-		interrupt-parent = <&gpio>;
+		interrupt-parent = <&rp1_gpio>;
 		interrupts = <37 IRQ_TYPE_LEVEL_LOW>;
 		eee-broken-1000t;
 		eee-broken-100tx;