drm/i915/kbl: Fix DMC load on Kabylake.

Kabylake A0 is based on Skylake H0.

v2: Don't assume revid+7 and only load the one we are sure about.

v3: Rebase on top of latest changes.

v4: Accept cleaner solution from Jani with kbl_stepping_info
    starting on H0 instead of put a hack on revid.

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449676319-6959-1-git-send-email-rodrigo.vivi@intel.com

drivers/gpu/drm/i915/intel_csr.c

@@ -166,6 +166,14 @@ struct stepping_info {
 	char substepping;
 };
 
+/*
+ * Kabylake derivated from Skylake H0, so SKL H0
+ * is the right firmware for KBL A0 (revid 0).
+ */
+static const struct stepping_info kbl_stepping_info[] = {
+	{'H', '0'}, {'I', '0'}
+};
+
 static const struct stepping_info skl_stepping_info[] = {
 	{'A', '0'}, {'B', '0'}, {'C', '0'},
 	{'D', '0'}, {'E', '0'}, {'F', '0'},
@@ -182,7 +190,10 @@ static const struct stepping_info *intel_get_stepping_info(struct drm_device *de
 	const struct stepping_info *si;
 	unsigned int size;
 
-	if (IS_SKYLAKE(dev)) {
+	if (IS_KABYLAKE(dev)) {
+		size = ARRAY_SIZE(kbl_stepping_info);
+		si = kbl_stepping_info;
+	} else if (IS_SKYLAKE(dev)) {
 		size = ARRAY_SIZE(skl_stepping_info);
 		si = skl_stepping_info;
 	} else if (IS_BROXTON(dev)) {