staging: wfx: drop useless include

ieee80211.h is useless since commit 5e911c3d ("staging: wfx: avoid
defining array of flexible struct")

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20220225112405.355599-7-Jerome.Pouiller@silabs.com


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