staging: wfx: drop unused enum wfx_state

In former code, the field wvif->state was more or less redundant with
vif->type. With the lasts change it has become unused. It is now time to
drop it.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200420160311.57323-16-Jerome.Pouiller@silabs.com


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