drm/i915/gt: Apply RCS workarounds to the render class

Treat all render engines to the RCS workarounds, simply to avoid using
engine->id when we are trying to think in terms of classes.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190705124325.14270-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_workarounds.c

@@ -1354,7 +1354,7 @@ engine_init_workarounds(struct intel_engine_cs *engine, struct i915_wa_list *wal
 	if (I915_SELFTEST_ONLY(INTEL_GEN(engine->i915) < 8))
 		return;
 
-	if (engine->id == RCS0)
+	if (engine->class == RENDER_CLASS)
 		rcs_engine_wa_init(engine, wal);
 	else
 		xcs_engine_wa_init(engine, wal);