media: hevc: Add sps_max_sub_layers_minus1 to v4l2_ctrl_hevc_sps

sps_max_sub_layers_minus1 is needed if the driver wishes to determine
whether or not a frame might be used for reference.
Signed-off-by: John Cox <jc@kynesim.co.uk>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst

@@ -2707,6 +2707,9 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
     * - __u8
       - ``chroma_format_idc``
       -
+    * - __u8
+      - ``sps_max_sub_layers_minus1``
+      -
     * - __u64
       - ``flags``
       - See :ref:`Sequence Parameter Set Flags <hevc_sps_flags>`

include/media/hevc-ctrls.h

@@ -75,8 +75,7 @@ struct v4l2_ctrl_hevc_sps {
 	__u8	num_short_term_ref_pic_sets;
 	__u8	num_long_term_ref_pics_sps;
 	__u8	chroma_format_idc;
-
-	__u8	padding;
+	__u8	sps_max_sub_layers_minus1;
 
 	__u64	flags;
 };