staging: wfx: drop useless enum hif_beacon

Enum hif_beacon is not used. Moreover, it is just another definition of
a boolean. Absolutely useless.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200907101521.66082-9-Jerome.Pouiller@silabs.com


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