mt76: mt7921: fix MT7921E reset failure

There is a missing mt7921e_driver_own in the MT7921E reset procedure
since the mt7921 mcu.c has been refactored for MT7921S, that will
result in MT7921E reset failure, so add it back now.

Fixes: dfc7743d

 ("mt76: mt7921: refactor mcu.c to be bus independent")
Reported-by: YN Chen <YN.Chen@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>