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

drivers/staging/wfx/hif_api_cmd.h

@@ -440,11 +440,6 @@ struct hif_cnf_start {
 	__le32 status;
 } __packed;
 
-enum hif_beacon {
-	HIF_BEACON_STOP                       = 0x0,
-	HIF_BEACON_START                      = 0x1
-};
-
 struct hif_req_beacon_transmit {
 	u8     enable_beaconing;
 	u8     reserved[3];