mt76: mt7921: abort uncompleted scan by wifi reset

Scan abort should be required for the uncompleted hardware scan
interrupted by wifi reset. Otherwise, it is possible that the scan
request after wifi reset gets error code -EBUSY from mac80211 and
then blocks the reconnectting to the access point.

Fixes: 0c1ce988 ("mt76: mt7921: add wifi reset support")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>