media: atomisp: Drop custom flash support

media: atomisp: Drop custom flash support

Remove the custom flash handling from the atomisp driver. There are
only few Bay Trail / Cherry Trail devices with flash and if those will
ever get supported then this should be done through the new standard
include/linux/led-class-flash.h APIs instead of with atomisp specific
custom APIs.

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>