media: vimc: move the dev field of each entity to vimc_ent_dev

Since the 'struct device *dev' field exists in each of the
entity structs, it can be moved to the common struct vimc_ent_devevice.
It is then used to replace 'pr_err' with 'dev_err' in the streamer
code.

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>