[media] v4l: vsp1: Create a new configure operation to setup modules

The subdev s_stream operation is abused as a generic way to setup
modules at every frame. Move the code out to a new VSP1 entity configure
operation.

Most modules now have an empty s_stream operation that can be removed.
The only exception is the WPF module that needs to perform hardware
configuration when stopping the stream. The code can be simplified
accordingly as we know that that operation never fails.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>