V4L/DVB (12906a): V4L : vpif display updates to support vpif capture

The structure name for vpif display driver changed since it was not unique. So this
update is done to reflect the same. Also removed the code related to register
address space iomap. Uses v4l2_i2c_new_subdev_board() instead of
v4l2_i2c_new_probed_subdev() so that platform data can be added for subdevice
configuration for polarities.

This has incorporated comments against version v0 of the patch series.

Resending the original patch for merge to V4L linux-next

Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Muralidharan Karicheri <m-karicheri2@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>