arm64: dts: mediatek: mt7986: drop "#reset-cells" from Ethernet controller

arm64: dts: mediatek: mt7986: drop "#reset-cells" from Ethernet controller

Ethernet block doesn't include or act as a reset controller.
Documentation also doesn't document "#reset-cells" for it.

This fixes:
arch/arm64/boot/dts/mediatek/mt7986a-bananapi-bpi-r3.dtb: ethernet@15100000: Unevaluated properties are not allowed ('#reset-cells' was unexpected)
        from schema $id: http://devicetree.org/schemas/net/mediatek,net.yaml#

Fixes: 082ff36bd5c0 ("arm64: dts: mediatek: mt7986: introduce ethernet nodes")
Cc: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240213053739.14387-2-zajec5@gmail.com
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>