wifi: mt76: mt7925: fix fw download fail

Add an address of fw region for fw download.

Fixes: c948b5da

 ("wifi: mt76: mt7925: add Mediatek Wi-Fi7 driver for mt7925 chips")
Signed-off-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>