media: atomisp: remove unused ia_css_frame_allocate_contiguous*() functions

ia_css_frame_allocate_contiguous() and
ia_css_frame_allocate_contiguous_from_info() are not used anywhere,
remove them.

Link: https://lore.kernel.org/linux-media/20220615205037.16549-3-hdegoede@redhat.com


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