brcmfmac: ignore interfaces when fwsignal is disabled

When brcmf_fws_add_interface() is called the struct brcmf_if::fws_desc
field is initialized regardless the state of the fwsignal functionality,
ie. the fcmode. This is not needed when fcmode is NONE, which is the
default mode.
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c

@@ -2145,7 +2145,7 @@ void brcmf_fws_add_interface(struct brcmf_if *ifp)
 	struct brcmf_fws_info *fws = ifp->drvr->fws;
 	struct brcmf_fws_mac_descriptor *entry;
 
-	if (!ifp->ndev)
+	if (!ifp->ndev || fws->fcmode == BRCMF_FWS_FCMODE_NONE)
 		return;
 
 	entry = &fws->desc.iface[ifp->ifidx];