Add `mdio_read_c45()`/`mdio_write_c45()` APIs for Clause 45 access
and remove the `protocol` MDIO binding property so that MDIO bus
controller can support more than one protocol.
A new MDIO header is introduced with generic opcodes, MMD and
registers addresses, to be used by MDIO and PHY drivers.
Existing MDIO drivers that support both Clause 22 and Clause 45
access are migrated to the new APIs.
Signed-off-by: Manuel Argüelles <manuel.arguelles@nxp.com>
Add MDIO driver that works through GPIO pins. This driver is
useful when a microcontroller doesn't have MDIO bus or when multiple
separate MDIO buses are required. The driver provides access to
the MDIO bus through GPIO pins for any SoC that has GPIO pin control
available.
Signed-off-by: Aleksandr Senin <al@meshium.net>
