mt76: mt7915: use proper aid value in mt7915_mcu_wtbl_generic_tlv in sta mode

mac80211 provides aid in vif->bss_conf.aid for sta mode and not in
sta->aid. Fix mt7915_mcu_wtbl_generic_tlv routine using proper value for
aid in sta mode.

Fixes: e57b7901 ("mt76: add mac80211 driver for MT7915 PCIe-based chipsets")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>