[media] soc_camera: error dev remove and v4l2 call

in soc_camera_close(), if ici->ops->remove() removes device firstly,
and then call __soc_camera_power_off(), it has logic error. Since
if remove device, it should disable subdev clk. but in __soc_camera_
power_off(), it will callback v4l2 s_power function which will
read/write subdev registers to control power by i2c. and then
i2c read/write will fail because of clk disable.
So suggest to re-sequence two functions call.
Change-Id: Iee7a6d4fc7c7c1addb5d342621eb8dcd00fa2745

Signed-off-by: Wenbing Wang <wangwb@marvell.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>