media: cedrus: h264: Fix 4K decoding on H6

Due to unknown reason, H6 needs larger intraprediction buffer for 4K
videos than other SoCs. This was discovered by playing 4096x2304 video,
which is maximum what H6 VPU is supposed to support.

Fixes: 03e612e7 ("media: cedrus: Fix H264 4k support")
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>