mt76: mt7615: add mt7663e support to mt7615_{driver,firmware}_own

Extend mt7615_driver_own and mt7615_firmware_own in order to reuse
them adding mt7663e support to mt7615 driver

Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Co-developed-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>