mgcp: Move transcoding to libmgcp

This patch moves the files relevant to transcoding from
src/osmo-bsc_mgcp to src/libmgcp and src/include/openbsc. Makefiles
and include directives are being updated accordingly.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/tests/mgcp/Makefile.am b/openbsc/tests/mgcp/Makefile.am
index 3982b07..ce9e596 100644
--- a/openbsc/tests/mgcp/Makefile.am
+++ b/openbsc/tests/mgcp/Makefile.am
@@ -18,7 +18,7 @@
 		$(LIBOSMOCORE_LIBS) -lrt -lm $(LIBOSMOSCCP_LIBS) $(LIBOSMOVTY_LIBS) \
 		$(LIBRARY_DL) $(LIBOSMONETIF_LIBS)
 
-mgcp_transcoding_test_SOURCES = mgcp_transcoding_test.c $(top_builddir)/src/osmo-bsc_mgcp/mgcp_transcode.c
+mgcp_transcoding_test_SOURCES = mgcp_transcoding_test.c
 
 mgcp_transcoding_test_LDADD = \
 		$(top_builddir)/src/libbsc/libbsc.a \