gbproxy: Rename PCU port to PCU_PTP; SGSN port to SGSN_PTP

This way it's more obvious that it refers to the PTP BVC, like we
already use PCU_SIG and SGSN_SIG for the signaling BVCs.

Change-Id: Ie8d327b0c6fae0e7963cc5907ab0bc94e97c67f3
1 file changed