wifi: mt76: mt7996: Update mt7996_mcu_add_sta to MLO support

Update mt7996_mcu_add_sta routine and all the called subroutines to
support MLO. This is a preliminary patch to enable MLO for MT7996
driver.

Co-developed-by: Bo Jiao <Bo.Jiao@mediatek.com>
Signed-off-by: Bo Jiao <Bo.Jiao@mediatek.com>
Co-developed-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250311-mt7996-mlo-v2-11-31df6972519b@kernel.org


Signed-off-by: Felix Fietkau <nbd@nbd.name>