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/src/libmgcp/Makefile.am b/openbsc/src/libmgcp/Makefile.am
index 262ad34..e5dab1a 100644
--- a/openbsc/src/libmgcp/Makefile.am
+++ b/openbsc/src/libmgcp/Makefile.am
@@ -1,9 +1,15 @@
 AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)
-AM_CFLAGS=-Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOVTY_CFLAGS) \
-	   $(LIBOSMONETIF_CFLAGS) $(COVERAGE_CFLAGS)
+AM_CFLAGS = -Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOVTY_CFLAGS) \
+	    $(LIBOSMONETIF_CFLAGS) $(COVERAGE_CFLAGS) $(LIBBCG729_CFLAGS)
 AM_LDFLAGS = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) \
-	     $(LIBOSMONETIF_LIBS) $(COVERAGE_LDFLAGS)
+	     $(LIBOSMONETIF_LIBS) $(COVERAGE_LDFLAGS) $(LIBBCG729_LIBS)
 
 noinst_LIBRARIES = libmgcp.a
 
+noinst_HEADERS = g711common.h
+
 libmgcp_a_SOURCES = mgcp_protocol.c mgcp_network.c mgcp_vty.c osmux.c
+
+if BUILD_MGCP_TRANSCODING
+    libmgcp_a_SOURCES += mgcp_transcode.c
+endif