tests: include headers from include/

In addition to .h files from src/ add include/ as well: some headers are
now public and reside in separate directory.

Change-Id: I09c02a171fb3b2f2791ce938725db7d4ff397e95
diff --git a/tests/Makefile.am b/tests/Makefile.am
index a03528c..79c3ef6 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,4 +1,4 @@
-AM_CPPFLAGS = $(STD_DEFINES_AND_INCLUDES) $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGB_CFLAGS) $(LIBOSMOGSM_CFLAGS) -I$(top_srcdir)/src/
+AM_CPPFLAGS = $(STD_DEFINES_AND_INCLUDES) $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGB_CFLAGS) $(LIBOSMOGSM_CFLAGS) -I$(top_srcdir)/src/ -I$(top_srcdir)/include/
 AM_LDFLAGS = -lrt
 
 check_PROGRAMS = rlcmac/RLCMACTest alloc/AllocTest tbf/TbfTest types/TypesTest ms/MsTest llist/LListTest llc/LlcTest codel/codel_test edge/EdgeTest bitcomp/BitcompTest fn/FnTest