Remove skb_ret parameter from mt7615_mcu_msg_send signature since it is
actually used just by mt7615_mcu_patch_sem_ctrl. This is a prelimanry
patch to use mt76 common mcu API
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>