mt76: mt7615: fix mt7615_firmware_own for mt7663e

Check the firmware-own configuration has been applied polling
MT_CONN_HIF_ON_LPCTL register

Fixes: f40ac0f3

 ("mt76: mt7615: introduce mt7663e support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>