drm/i915/csr: Added ICL Stepping info

As DMC Package contain DMC FW for multiple steppings including default
stepping. This patch will help to load FW for that particular stepping,
if FW for that stepping is available, instead of loading default FW.

v2 : Fix formatting issue.
Signed-off-by: Jyoti Yadav <jyoti.r.yadav@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1536169347-31326-1-git-send-email-jyoti.r.yadav@intel.com

drivers/gpu/drm/i915/intel_csr.c

@@ -191,6 +191,12 @@ static const struct stepping_info bxt_stepping_info[] = {
 	{'B', '0'}, {'B', '1'}, {'B', '2'}
 };
 
+static const struct stepping_info icl_stepping_info[] = {
+	{'A', '0'}, {'A', '1'}, {'A', '2'},
+	{'B', '0'}, {'B', '2'},
+	{'C', '0'}
+};
+
 static const struct stepping_info no_stepping_info = { '*', '*' };
 
 static const struct stepping_info *
@@ -199,7 +205,10 @@ intel_get_stepping_info(struct drm_i915_private *dev_priv)
 	const struct stepping_info *si;
 	unsigned int size;
 
-	if (IS_SKYLAKE(dev_priv)) {
+	if (IS_ICELAKE(dev_priv)) {
+		size = ARRAY_SIZE(icl_stepping_info);
+		si = icl_stepping_info;
+	} else if (IS_SKYLAKE(dev_priv)) {
 		size = ARRAY_SIZE(skl_stepping_info);
 		si = skl_stepping_info;
 	} else if (IS_BROXTON(dev_priv)) {