Drivers implementing custom ioctls need to handle 32-bit/64-bit
compatibility themselves. Provide them with a way to do so.
To avoid circular module dependencies, merge the v4l2-compat-ioctl32
module into videodev. There is no point in keeping them separate, as the
v4l2_compat_ioctl32() function is required by videodev if CONFIG_COMPAT
is set anyway.