[sun4i_csi] Add power_on/power_off/stby_on/stby_off function to camera sub
driver.

Signed-off-by: Anatoliy Sokolov <aesok@post.ru>
[sun3i_csi] Add v4l2_subdev_internal_ops and 'registered' method to camera
sub driver. Call <module>_detect from 'registered' method.

Signed-off-by: Anatoliy Sokolov <aesok@post.ru>
[sun4i_csi] Remove code for power on/off camera module from csi_porbe
function.

Signed-off-by: Anatoliy Sokolov <aesok@post.ru>
[sun4i_csi] Remove 'sensor_detect' function call from sensor_init function.

Signed-off-by: Anatoliy Sokolov <aesok@post.ru>