When supporting Rpi Camera v2 Module on the RZ/G2E, found the driver had
some issues with rcar mipi-csi driver. The sensor never entered into LP-11
state.

The powerup sequence in the datasheet[1] shows the sensor entering into
LP-11 in streaming mode, so to fix this issue transitions are performed
from "streaming -> standby" in the probe() after power up.

With this commit the sensor is able to enter LP-11 mode during power up,
as expected by some CSI-2 controllers.

[1] https://publiclab.org/system/images/photos/000/023/294/original/
RASPBERRY_PI_CAMERA_V2_DATASHEET_IMX219PQH5_7.0.0_Datasheet_XXX.PDF
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>