Add 'include' directory for test.
Add 'include' directory for test.

The binaries in the test directory won't build successfully for me
without adding this include path.

Signed-off-by: Trevor Woerner <8835777cd84fba3d7873eabbbe1f2de2d3f25b00@gmail.com>
Signed-off-by: Peter Hutterer <b9c50af7afa7642f6f854434cda9ffe54ece8b85@who-t.net>

mad-s/xf86-input-synaptics-absolute,mad-s/xf86-input-synaptics-absolute