realtek: early ethernet probe in dsa setup
The ethernet and mdio code will be splitted. The dsa driver depends
on proper loading of both, before switch setup can start. Sadly there
are severe cleanup issues in the probe() function if one of the
required devices is not available.
As a temporary workaround provide a dedicated check function that
verifies if the ethernet platform device driver is loaded and can
be used.
Signed-off-by: Markus Stockhausen <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19942
Signed-off-by: Robert Marko <[email protected]>