gsm/ipa: Add segmentation callback

Add segmentation callback to be used by the streaming backend of libosmo-netif

Related: OS#5753, OS#5751
Change-Id: I3a639e6896cc3b3fc8e9b2e1a58254710efa0d3f
diff --git a/include/osmocom/gsm/ipa.h b/include/osmocom/gsm/ipa.h
index 851b58e..8a4dd3f 100644
--- a/include/osmocom/gsm/ipa.h
+++ b/include/osmocom/gsm/ipa.h
@@ -79,3 +79,6 @@
 
 int ipa_msg_recv(int fd, struct msgb **rmsg);
 int ipa_msg_recv_buffered(int fd, struct msgb **rmsg, struct msgb **tmp_msg);
+
+/* Callback for segmenting TCP stream data into IPA packets */
+int ipa_segmentation_cb(struct msgb *msg);