media: marvell-ccic: Use v4l2_async_notifier_add_*_subdev
The use of v4l2_async_notifier_add_subdev will be discouraged.
Drivers are instead encouraged to use a helper such as
v4l2_async_notifier_add_fwnode_remote_subdev.
This fixes a misuse of the API, as v4l2_async_notifier_add_subdev
should get a kmalloc'ed struct v4l2_async_subdev,
removing some boilerplate code while at it.
Use the appropriate helper: v4l2_async_notifier_add_i2c_subdev
or v4l2_async_notifier_add_fwnode_remote_subdev, which handles
the needed setup, instead of open-coding it.