arm64: dts: broadcom: bcmbca: bcm4908: drop invalid switch cells

arm64: dts: broadcom: bcmbca: bcm4908: drop invalid switch cells

Ethernet switch does not have addressable subnodes.

This fixes:
arch/arm64/boot/dts/broadcom/bcmbca/bcm4908-asus-gt-ac5300.dtb: ethernet-switch@0: '#address-cells', '#size-cells' do not match any of the regexes: 'pinctrl-[0-9]+'
        from schema $id: http://devicetree.org/schemas/net/dsa/brcm,sf2.yaml#

Fixes: 527a3ac9bdf8 ("arm64: dts: broadcom: bcm4908: describe internal switch")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20240111115636.12095-1-zajec5@gmail.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>