Add check for CTest module include

add_test function should only be used if the CTest module is included
in the root CMakeLists.txt. unit_test_add_suite() function now verifies
this condition.

Change-Id: I39821798e24844caeab6196eb31875e5d3d60f1d
Signed-off-by: Imre Kis <imre.kis@arm.com>
1 file changed