wifi: mt76: mt7996: set correct value in beamforming mcu command for mt7992

Configure correct bf number and bitmap in beamforming mcu command for
mt7992 chipsets, which only support dual-band.

Signed-off-by: Howard Hsu <howard-yh.hsu@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Link: https://patch.msgid.link/20240816094635.2391-8-shayne.chen@mediatek.com


Signed-off-by: Felix Fietkau <nbd@nbd.name>