wifi: mt76: mt7925: update mt76_connac_mcu_uni_add_dev for MLO

wifi: mt76: mt7925: update mt76_connac_mcu_uni_add_dev for MLO

Set OMAC address with the per-link BSS. The change remains compatible with
the non-MLO mode and the older firmware.

Co-developed-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Signed-off-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Co-developed-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Link: https://patch.msgid.link/6b2502d0c3a53093f83ae33329e9d782ba2465b3.1720042294.git.sean.wang@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>