media: atomisp: Convert to videobuf2

Convert atomisp to use videobuf2.

This fixes mmap not working and in general moving over to
the more modern videobuf2 is a good plan.

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>