drm/i915/chv: Remove Wait for a previous gfx force-off

On CHV, PUNIT team confirmed that 'VLV_GFX_CLK_STATUS_BIT' is not a
sticky bit and it will always be set. So ignore Check for previous
Gfx force off during suspend and allow the force clk as part S0ix
Sequence

Signed-off-by: Deepak S <deepak.s@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -1194,11 +1194,13 @@ int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool force_on)
 	int err;
 
 	val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
-	WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
 
 #define COND (I915_READ(VLV_GTLC_SURVIVABILITY_REG) & VLV_GFX_CLK_STATUS_BIT)
 	/* Wait for a previous force-off to settle */
-	if (force_on) {
+	if (force_on && !IS_CHERRYVIEW(dev_priv->dev)) {
+		/* WARN_ON only for the Valleyview */
+		WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
+
 		err = wait_for(!COND, 20);
 		if (err) {
 			DRM_ERROR("timeout waiting for GFX clock force-off (%08x)\n",