Add support for the four new variants of ioctl commands for 64-bit time_t
in v4l2_buffer.

The existing v4l2_buffer32 structure for the traditional format gets
changed to match the new v4l2_buffer format, and the old layout is
now called v4l2_buffer32_time32. Neither of these matches the native
64-bit architecture format of v4l2_buffer, so both require special
handling in compat code.

Duplicating the existing handlers for the new types is a safe conversion
for now, but unfortunately this may turn into a maintenance burden
later. A larger-scale rework of the compat code might be a better
alternative, but is out of scope of the y2038 work.

Note: x32 support for v4l2_buffer32 has always been broken and remains
so after this change, fixing it would have required even more duplication,
and apparently nobody has cared so far.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: remove spurious newline]
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>