mt76: mt7615: configure bss info adding the interface

Introduce essential bss information for multiple vifs hw_scan in
mt7615_mcu_uni_add_dev adding the interface

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