[dist] Fix make distcheck by adding the new header files
diff --git a/include/openbsc/Makefile.am b/include/openbsc/Makefile.am
index d3be438..1bc3bc3 100644
--- a/include/openbsc/Makefile.am
+++ b/include/openbsc/Makefile.am
@@ -1,3 +1,4 @@
noinst_HEADERS = abis_nm.h abis_rsl.h debug.h db.h gsm_04_08.h gsm_data.h \
gsm_subscriber.h linuxlist.h msgb.h select.h tlv.h gsm_04_11.h \
- timer.h misdn.h chan_alloc.h telnet_interface.h paging.h
+ timer.h misdn.h chan_alloc.h telnet_interface.h paging.h \
+ subchan_demux.h trau_frame.h