wl1271: Implement delayed entry into ELP

Implement delayed entry into ELP. This will promote the following:
 - Less redundant sleep/wake cycles (better perf)
 - Avoids known firmware issues with going to ELP too fast after an
   operation

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Vidhya Govindan <vidhya.govindan@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/wl12xx/wl1271_ps.h b/drivers/net/wireless/wl12xx/wl1271_ps.h
index de2bd3c..779653d 100644
--- a/drivers/net/wireless/wl12xx/wl1271_ps.h
+++ b/drivers/net/wireless/wl12xx/wl1271_ps.h
@@ -30,6 +30,6 @@
 int wl1271_ps_set_mode(struct wl1271 *wl, enum wl1271_cmd_ps_mode mode);
 void wl1271_ps_elp_sleep(struct wl1271 *wl);
 int wl1271_ps_elp_wakeup(struct wl1271 *wl, bool chip_awake);
-
+void wl1271_elp_work(struct work_struct *work);
 
 #endif /* __WL1271_PS_H__ */