ARM: dts: dove.dtsi: Move ethphy to fix schema error

Running 'make dtbs_check' with schema in net/marvell,orion-mdio.yaml
gives following warnings:
mdio-bus@72004: Unevaluated properties are not allowed
('ethernet-phy' was unexpected)
	arch/arm/boot/dts/dove-cubox.dtb
	arch/arm/boot/dts/dove-cubox-es.dtb
	arch/arm/boot/dts/dove-d2plug.dtb
	arch/arm/boot/dts/dove-d2plug.dtb
	arch/arm/boot/dts/dove-dove-db.dtb
	arch/arm/boot/dts/dove-d3plug.dtb
	arch/arm/boot/dts/dove-sbc-a510.dtb
As every subnode of mdio is expected to have an @X, ethernet-phy subnode
in dove.dtsi doesn't have one. Fix these errors by moving ethernet-phy
into relevant .dts files with correct @<reg address>.

Signed-off-by: Michał Grzelak <mig@semihalf.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>