net: phy: Add the Airoha EN8811H PHY driver

net: phy: Add the Airoha EN8811H PHY driver

Add the driver for the Airoha EN8811H 2.5 Gigabit PHY. The PHY supports
100/1000/2500 Mbps with auto negotiation only.

The driver uses two firmware files, for which updated versions are added to
linux-firmware already.

Based on the Linux upstream 8811 driver code(air_en8811h.c),
I have modified the relevant process to align with the U-Boot boot sequence.
and have validated this on Banana Pi BPI-R3 Mini.

The MD32 FW is currently stored in eMMC partition 1 on Banana Pi BPI-R3 Mini,
and it is loaded from there.

Signed-off-by: Lucien.Jheng <lucienzx159@gmail.com>