media: i2c: ov5647: Initialize subdev before controls

In the Linux kernel, the following vulnerability has been resolved:

media: i2c: ov5647: Initialize subdev before controls

In ov5647_init_controls() we call v4l2_get_subdevdata, but it is

initialized by v4l2_i2c_subdev_init() in the probe, which currently

happens after init_controls(). This can result in a segfault if the

error condition is hit, and we try to access i2c_client, so fix the

order.