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>