media: atomisp: remove compat_ioctl32 code

This is one of the last remaining users of compat_alloc_user_space()
and copy_in_user(), which are in the process of getting removed.

As of commit 57e6b6f2 ("media: atomisp_fops.c: disable
atomisp_compat_ioctl32"), nothing in this file is actually getting used
as the only reference has been stubbed out.

Remove the entire file -- anyone willing to restore the functionality
can equally well just look up the contents in the git history if needed.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>