arm64: dts: rockchip: Simplify network PHY connection on qnap-ts433

arm64: dts: rockchip: Simplify network PHY connection on qnap-ts433

While it requires to have the right phy driver loaded (i.e. motorcomm)
to make the phy asserting the right delays, this is generally the
preferred way to define the MAC <-> PHY connection.

Signed-off-by: Uwe Kleine-König <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Stuebner <[email protected]>
[ upstream commit: e8d45544f806f3b55c30345de84262cbb9504902 ]

(cherry picked from commit e0bbe061fd537bd7b113c53eb046bbcbf0e6597d)
Reviewed-by: Kever Yang <[email protected]>