r8169: consider that PHY reset may still be in progress after applying firmware

Some firmware files trigger a PHY soft reset and don't wait for it to
be finished. PHY register writes directly after applying the firmware
may fail or provide unexpected results therefore. Fix this by waiting
for bit BMCR_RESET to be cleared after applying firmware.

There's nothing wrong with the referenced change, it's just that the
fix will apply cleanly only after this change.

Fixes: 89fbd26c ("r8169: fix firmware not resetting tp->ocp_base")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>