net: mdio: scan bus based on bus capabilities for C22 and C45

Now that all MDIO bus drivers which set probe_capabilities to
MDIOBUS_C22_C45 have been converted to use the name API for C45
transactions, perform the scanning of the bus based on which methods
the bus provides.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>