staging: brcm80211: remove dhd_set_timer function prototype

This function prototype is not implemented nor referenced in the
brcmfmac driver so it has been removed.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/brcm80211/brcmfmac/dhd_common.c

@@ -66,8 +66,6 @@ const char dhd_version[] =
 const char dhd_version[] = "Dongle Host Driver, version " EPI_VERSION_STR;
 #endif
 
-void dhd_set_timer(void *bus, uint wdtick);
-
 /* IOVar table */
 enum {
 	IOV_VERSION = 1,