staging: wfx: allow to receive 802.11 frames

Again, this task is more complex than it should since driver try to
handle itself power saving of stations.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20190919142527.31797-18-Jerome.Pouiller@silabs.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>