test/cunit/Makefile: fix OOT build
test/cunit/Makefile: fix OOT build

make[4]: Entering directory
'/random-scripts/ofp-packaging/openfastpath-1.0.git232.ga4b9e07/test/cunit'
  CC       ofp_test_debug_pcap.o
ofp_test_debug_pcap.c:26:29: fatal error: test_raw_frames.h: No such
file or directory
 #include "test_raw_frames.h"
                             ^
compilation terminated.

Signed-off-by: Anders Roxell <b4e8e89057bc64bc4f9625a4a821c9ac177a7ed2@linaro.org>
Reviewed-by: Sorin Vultureanu <8013ba55f8675034bc2ab0d6c3a1c9650437ca36@enea.com>

OpenFastPath/ofp,TolikH/ofp,OpenFastPath/ofp,OpenFastPath/ofp,TolikH/ofp,TolikH/ofp,OpenFastPath/ofp