wifi: mt76: mt7915: Fix mesh scan on MT7916 DBDC

wifi: mt76: mt7915: Fix mesh scan on MT7916 DBDC

commit c4f075582304 ("wifi: mt76: mt7915: fix command timeout in AP stop
period") changes the behavior of mt7915_bss_info_changed() in mesh mode
when enable_beacon becomes false: it calls mt7915_mcu_add_bss_info(...,
false) and mt7915_mcu_add_sta(..., false) while the previous code
didn't.  These sends mcu commands that apparently confuse the firmware.

This breaks scanning while in mesh mode on AsiaRF MT7916 DBDC-based cards:
scanning works but no mesh frames get sent afterwards and the firmware
seems to be hosed.  It breaks on MT7916 DBDC but not on MT7915 DBDC.

Fixes: c4f075582304 ("wifi: mt76: mt7915: fix command timeout in AP stop period")
Signed-off-by: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
Link: https://patch.msgid.link/20240927085350.4594-1-nicolas.cavallari@green-communications.fr
Signed-off-by: Felix Fietkau <nbd@nbd.name>