mt76: mt7921: switch to new api for hardware beacon filter

Current firmware only supports new api for enabling hardware beacon filter.

Fixes: 1d8efc74 ("mt76: mt7921: introduce Runtime PM support")
Beacon filter cmd have to rely on the associatied access point's beacon
interval and DTIM information.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>