igt: Start marking up GEM tests that require an alive GPU to function

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/tests/gem_exec_schedule.c b/tests/gem_exec_schedule.c
index b3f61fe..168faaa 100644
--- a/tests/gem_exec_schedule.c
+++ b/tests/gem_exec_schedule.c
@@ -457,6 +457,7 @@
 
 	igt_fixture {
 		fd = drm_open_driver_master(DRIVER_INTEL);
+		igt_require_gem(fd);
 		gem_require_mmap_wc(fd);
 		igt_fork_hang_detector(fd);
 	}