move headers to include/osmocom/hlr

Apply the same headers structure that we keep in most Osmocom source trees:
Keep noinst_HEADERS in include/osmocom/hlr and include them using
  #include <osmocom/hlr/*.h>

The only header kept in src/ is db_bootstrap.h, because it is generated during
build time. If it was built in include/osmocom/hlr, we would need db.o to
depend on db_bootstrap.h in a different subdir, which automake can't do well.

Change-Id: Ic912fe27f545b85443c5fb713d8c3c8aac23c9ad
diff --git a/include/osmocom/hlr/Makefile.am b/include/osmocom/hlr/Makefile.am
new file mode 100644
index 0000000..77a8764
--- /dev/null
+++ b/include/osmocom/hlr/Makefile.am
@@ -0,0 +1,14 @@
+noinst_HEADERS = \
+	auc.h \
+	ctrl.h \
+	db.h \
+	gsup_router.h \
+	gsup_server.h \
+	hlr.h \
+	hlr_ussd.h \
+	hlr_vty.h \
+	hlr_vty_subscr.h \
+	logging.h \
+	luop.h \
+	rand.h \
+	$(NULL)