Revert "net: ethernet: stmmac: dwmac-rk: Make the clk_phy could be used for external phy"

This reverts commit da114122.

As discussed, the PHY clock should be managed by PHY driver instead
of other driver like dwmac-rk.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/a30a8c97-6b96-45ba-bad7-8a40401babc2@samsung.com


Fixes: da114122 ("net: ethernet: stmmac: dwmac-rk: Make the clk_phy could be used for external phy")
Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
Link: https://patch.msgid.link/0A3F1D1604FEE424+20250916012628.1819-1-kernel@airkyi.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>