media: cedrus: Don't kernel map most buffers

Except for VP8 probability coefficients buffer, all other buffers are
never accessed by CPU. That allows us to mark them with
DMA_ATTR_NO_KERNEL_MAPPING flag. This helps with decoding big (like 4k)
videos on 32-bit ARM platforms where default vmalloc size is relatively
small - 240 MiB. Since auxiliary buffer are not yet efficiently
allocated, this can be easily exceeded. Even if allocation is optimized,
4k videos will still often exceed this limit.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>