drm/i915/selftests: Skip the execlists tests on !execlists machines

Ignore the tests looking at the innards of execlists and its submission
tasklets on machines that don't support execlists!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180504124202.24894-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/selftests/intel_lrc.c

@@ -505,5 +505,9 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(live_preempt),
 		SUBTEST(live_late_preempt),
 	};
+
+	if (!HAS_EXECLISTS(i915))
+		return 0;
+
 	return i915_subtests(tests, i915);
 }