Fix conditional compilation issues.

Fixed include directory settings and conditional includes in CMakeLists and test_common.c. Refs #1085.

test_apps/main/test_common.c

@@ -6,7 +6,10 @@
 
 #include "test_common.h"
 #include "relay_chn_ctl.h" // For resetting the channels
+
+#if CONFIG_RELAY_CHN_ENABLE_TILTING
 #include "relay_chn_tilt.h" // For resetting tilt count
+#endif
 
 const char *TEST_TAG = "RELAY_CHN_TEST";