wl1271: Fix beacon filter table configuration

The beacon filter table configuration ACX structure had certain elements
reversed, resulting in firmware instability in regard of the feature. Fix
the structure.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>