media: rcar-vin: Move pm_runtime_{get,put} out of helpers

The helpers rvin_power_{on,off} deal with both VIN and the parallel
subdevice power. This makes it hard to merge the Gen2 and Gen3
open/release functions. Move the VIN power handling directly to the
open/release functions to prepare for the merge.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>