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_nop.c b/tests/gem_exec_nop.c
index 0d7a4d0..5a2f1b9 100644
--- a/tests/gem_exec_nop.c
+++ b/tests/gem_exec_nop.c
@@ -451,6 +451,7 @@
 		const uint32_t bbe = MI_BATCH_BUFFER_END;
 
 		device = drm_open_driver(DRIVER_INTEL);
+		igt_require_gem(device);
 		print_welcome(device);
 
 		handle = gem_create(device, 4096);