mt76: mt7615: use new tag sta_rec_wtbl

In order to reduce command/event times, newer firmware adds a tag
sta_rec_wtbl to take care of WTBL operations.

MCU_EXT_CMD_WTBL_UPDATE is deprecated.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Tested-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>