net: phy: realtek: reunify C22 and C45 drivers

net: phy: realtek: reunify C22 and C45 drivers

Reunify the split C22/C45 drivers for the RTL8221B-VB-CG 2.5Gbps and
RTL8221B-VM-CG 2.5Gbps PHYs back into a single driver.

This is possible now by using all the driver operations previously used
by the C45 driver, as transparent access to all MMDs including
MDIO_MMD_VEND2 is now possible also over Clause-22 MDIO.

The unified driver will still only use Clause-45 access on any Clause-45
capable busses while still working fine on Clause-22 busses.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/bffcb85fdc20e07056976962d3caaa1be5d0ddb0.1768275364.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>