[ipa] Make sending of ID REQ public...

Make sending of the ID Request message public. We are going
to use this in the BSC NAT code to ask for querying the BSC.
diff --git a/openbsc/include/openbsc/ipaccess.h b/openbsc/include/openbsc/ipaccess.h
index dbd9f37..76acf7c 100644
--- a/openbsc/include/openbsc/ipaccess.h
+++ b/openbsc/include/openbsc/ipaccess.h
@@ -49,6 +49,7 @@
 struct msgb *ipaccess_read_msg(struct bsc_fd *bfd, int *error);
 void ipaccess_prepend_header(struct msgb *msg, int proto);
 int ipaccess_send_id_ack(int fd);
+int ipaccess_send_id_req(int fd);
 
 /*
  * Firmware specific header