wifi: mt76: mt7996: Move mlink deallocation in mt7996_vif_link_remove()

wifi: mt76: mt7996: Move mlink deallocation in mt7996_vif_link_remove()

Destroy mt76_vif_link struct in mt7996_vif_link_remove routine and not
in mt76_unassign_vif_chanctx(). This is necessary since, in order to
properly support MLO link reconfiguration, we will destroy mt76_vif_link
struct during AP tear-down process and not running unassign_vif_chanctx
mac80211 callback.
This patch does not introduce any regression since
mt76_assign_vif_chanctx/mt76_unassign_vif_chanctx APIs are currently
used just by MT7996 driver.

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/20260315-mt7996-mlo-link-reconf-v1-3-a8a634fbc927@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>