Remove unused function prototype

This function was not added, so the prototype should not have been here
either.

Signed-hostap: Jouni Malinen <j@w1.fi>

wpa_supplicant/wpa_supplicant_i.h

@@ -754,7 +754,6 @@ void wpas_clear_temp_disabled(struct wpa_supplicant *wpa_s,
 int disallowed_bssid(struct wpa_supplicant *wpa_s, const u8 *bssid);
 int disallowed_ssid(struct wpa_supplicant *wpa_s, const u8 *ssid,
 		    size_t ssid_len);
-void wpa_supplicant_proc_40mhz_intolerant(struct wpa_supplicant *wpa_s);
 
 /**
  * wpa_supplicant_ctrl_iface_ctrl_rsp_handle - Handle a control response