media: ti: omap4iss: Use media_pipeline_for_each_entity()

media: ti: omap4iss: Use media_pipeline_for_each_entity()

Replace usage of the deprecated media graph walk API with the new
media_pipeline_for_each_entity() and media_pipeline_for_each_pad()
macros.

Even though the entity iterator may seem a better match when build the
entity bitmap in iss_video_stream(), it would not be more efficient as
it would still iterate internally over all pads. As the entity iterator
requires explicit iterator initialization and cleanup calls, the code
would be more complex.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>