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.

Note: At phy-address + 8 there is another device on the mdio bus, that
belongs to the EN881H. While the original driver writes to it, Airoha
has confirmed this is not needed. Therefore, communication with this
device is not included in this driver.
Signed-off-by: Eric Woudstra <ericwouds@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240326162305.303598-3-ericwouds@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>