media: vim2m: Add parametized support for multiplanar API

media: vim2m: Add parametized support for multiplanar API

Add support for the mulitiplaner API. The device can now act as
either a multi-planar or a single-planar device depending on a module
parameter, similar to the way vivid behaves.

Multiplanar support was added by implementing the appropate
try/get/set mplane functions, and by modifying the queue_setup() and
buf_prepare() functions to handle multiple planes. Implementation
was inspired by vivid.

Signed-off-by: Matthew Majewski <mattwmajewski@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>