media: v4l2: Rename second ioctl handlers argument to 'void *priv'

media: v4l2: Rename second ioctl handlers argument to 'void *priv'

The second argument to the ioctl handlers is not a file handle any more.
The standard practice is to name it 'void *priv' in drivers. Many
drivers still name it 'void *fh', and a few use more exotic names.
Replace those more exotic names with 'void *priv' in all media drivers.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Jai Luthra <jai.luthra@linux.dev>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>