drm/i915/skl: Fix stepping check for a couple of W/As

Both WaDisableSDEUnitClockGating and WaSetGAPSunitClckGateDisable are
needed on B0 as well.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -67,7 +67,7 @@ static void skl_init_clock_gating(struct drm_device *dev)
 
 	gen9_init_clock_gating(dev);
 
-	if (INTEL_REVID(dev) == SKL_REVID_A0) {
+	if (INTEL_REVID(dev) <= SKL_REVID_B0) {
 		/*
 		 * WaDisableSDEUnitClockGating:skl
 		 * WaSetGAPSunitClckGateDisable:skl