staging: wlan-ng: fix bad symbol declaration

With sparse, the following error appears :
  CHECK   drivers/staging/wlan-ng/p80211netdev.c
drivers/staging/wlan-ng/cfg80211.c:710:6: warning: symbol 'prism2_connect_result' was not declared. Should it be static?
drivers/staging/wlan-ng/cfg80211.c:719:6: warning: symbol 'prism2_disconnected' was not declared. Should it be static?
drivers/staging/wlan-ng/cfg80211.c:725:6: warning: symbol 'prism2_roamed' was not declared. Should it be static?

Move functions declaration to coherent internal header file.
Signed-off-by: Neil 'Superna' Armstrong <superna9999@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/prism2mgmt.h

@@ -109,4 +109,9 @@ void prism2sta_processing_defer(struct work_struct *data);
 void prism2sta_commsqual_defer(struct work_struct *data);
 void prism2sta_commsqual_timer(unsigned long data);
 
+/* Interface callback functions, passing data back up to the cfg80211 layer */
+void prism2_connect_result(wlandevice_t *wlandev, u8 failed);
+void prism2_disconnected(wlandevice_t *wlandev);
+void prism2_roamed(wlandevice_t *wlandev);
+
 #endif

drivers/staging/wlan-ng/prism2sta.c

@@ -120,10 +120,6 @@ MODULE_PARM_DESC(prism2_reset_settletime, "reset settle time in ms");
 
 MODULE_LICENSE("Dual MPL/GPL");
 
-void prism2_connect_result(wlandevice_t *wlandev, u8 failed);
-void prism2_disconnected(wlandevice_t *wlandev);
-void prism2_roamed(wlandevice_t *wlandev);
-
 static int prism2sta_open(wlandevice_t *wlandev);
 static int prism2sta_close(wlandevice_t *wlandev);
 static void prism2sta_reset(wlandevice_t *wlandev);