The partition algorithm needs to determine the capabilities of each
entity in the pipeline to identify the correct maximum partition width.

Extend the vsp1 entity operations to provide a max_width operation and
use this call to calculate the number of partitions that will be
processed by the algorithm.

Gen 2 hardware does not require multiple partitioning, and as such
will always return a single partition.
Signed-off-by: Kieran Bingham <kieran+renesas@bingham.xyz>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>