media: coda: Add a V4L2 user for control error macroblocks count

To avoid potentially overflowing the kernel logs in the case
of corrupted streams, this commit replaces an error message with
a per-stream counter to be read through a driver-specific
control.

Applications can read the per-stream accumulated
error macroblocks count.

The old error message is replaced by a rate-limited debug message.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>