trau: Introduce osmo_rtp_socket_set_priority()

For consistency reasons with osmo_rtp_socket_set_dscp(), let's also
introduce a osmo_rtp_socket_set_priority() function to wrap the two
calls to osmo_sock_set_priority().

Change-Id: I52c08f4b2a46981d002ef0c21e6549445d845a6e
diff --git a/include/osmocom/trau/osmo_ortp.h b/include/osmocom/trau/osmo_ortp.h
index 1e0720c..4cf2321 100644
--- a/include/osmocom/trau/osmo_ortp.h
+++ b/include/osmocom/trau/osmo_ortp.h
@@ -77,6 +77,7 @@
 int osmo_rtp_socket_autoconnect(struct osmo_rtp_socket *rs);
 int osmo_rtp_socket_set_pt(struct osmo_rtp_socket *rs, int payload_type);
 int osmo_rtp_socket_set_dscp(struct osmo_rtp_socket *rs, int dscp);
+int osmo_rtp_socket_set_priority(struct osmo_rtp_socket *rs, uint8_t prio);
 int osmo_rtp_socket_free(struct osmo_rtp_socket *rs);
 int osmo_rtp_skipped_frame(struct osmo_rtp_socket *rs, unsigned int duration);
 int osmo_rtp_send_frame(struct osmo_rtp_socket *rs, const uint8_t *payload,