drm/i915/skl: Fix DMC load on Skylake J0 and K0

BugLink: http://bugs.launchpad.net/bugs/1580754

commit a41c8882 upstream.

The driver does not load firmware for unknown steppings, so these new
steppings must be added to the list.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1454023163-25469-1-git-send-email-mathew.j.martineau@linux.intel.com
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/gpu/drm/i915/intel_csr.c

@@ -180,7 +180,8 @@ struct stepping_info {
 static const struct stepping_info skl_stepping_info[] = {
 		{'A', '0'}, {'B', '0'}, {'C', '0'},
 		{'D', '0'}, {'E', '0'}, {'F', '0'},
-		{'G', '0'}, {'H', '0'}, {'I', '0'}
+		{'G', '0'}, {'H', '0'}, {'I', '0'},
+		{'J', '0'}, {'K', '0'}
 };
 
 static struct stepping_info bxt_stepping_info[] = {