Merge branch 'net-mdio-remove-support-for-building-c45-muxed-addresses'

Michael Walle says:

====================
net: mdio: Remove support for building C45 muxed addresses

I've picked this older series from Andrew up and rebased it onto
the latest net-next.

With all drivers which support c45 now being converted to a seperate c22
and c45 access op, we can now remove the old MII_ADDR_C45 flag.
====================

Link: https://lore.kernel.org/r/20230119130700.440601-1-michael@walle.cc
Signed-off-by: Jakub Kicinski <kuba@kernel.org>