media: atomisp: Remove file-injection support

The file-injection support of the atomisp driver has not been tested
and is not necessary for camera support, remove it.

Note the main reason for removing this is because it depends on
the videobuf (version 1) outq and we want to remove or replace
all videobuf usage in the driver.

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