davinci: DM355 - platform changes for vpfe capture

DM355 platform and board setup

This has platform and board setup changes to support vpfe capture
driver for DM355 EVMs.

Tested video capture on DM355 using tvp514x

Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Reviewed-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Reviewed-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Muralidharan Karicheri <m-karicheri2@ti.com>
Signed-off-by: Denys Dmytriyenko <denis@denix.org>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>