Fix non-P2P build after the P2P_DEVICE changes

Commit c68f6200a72f2b33304f583859b09e57757b9d2a added a call to a
function that exists only for P2P builds. Fix that with #ifdef
CONFIG_P2P.

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

wpa_supplicant/main.c

@@ -307,11 +307,13 @@ int main(int argc, char *argv[])
 			exitcode = -1;
 			break;
 		}
+#ifdef CONFIG_P2P
 		if (wpa_s->global->p2p == NULL &&
 		    (wpa_s->drv_flags &
 		     WPA_DRIVER_FLAGS_DEDICATED_P2P_DEVICE) &&
 		    wpas_p2p_add_p2pdev_interface(wpa_s) < 0)
 			exitcode = -1;
+#endif /* CONFIG_P2P */
 	}
 
 	if (exitcode == 0)