media: hantro: postproc: Fix buffer size calculation

When allocating aux buffers for postprocessing, it's assumed that base
buffer size is the same as that of output. Coincidentally, that's true
most of the time, but not always. 10-bit source also needs aux buffer
size which is appropriate for 10-bit native format, even if the output
format is 8-bit. Similarly, mv sizes and other extra buffer size also
depends on source width/height, not destination.

Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Tested-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
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@kernel.org>