media: Documentation: v4l: Document missing async subdev function

Also v4l2_async_nf_add_fwnode() may be used to add an async sub-device
descriptor to a notifier. Document this. Also remove a redundant sentence.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

Documentation/driver-api/media/v4l2-subdev.rst

@@ -206,15 +206,11 @@ takes two arguments: a pointer to struct :c:type:`v4l2_device` and a
 pointer to struct :c:type:`v4l2_async_notifier`.
 
 Before registering the notifier, bridge drivers must do two things: first, the
-notifier must be initialized using the :c:func:`v4l2_async_nf_init`.
-Second, bridge drivers can then begin to form a list of subdevice descriptors
-that the bridge device needs for its operation. Several functions are available
-to add subdevice descriptors to a notifier, depending on the type of device and
-the needs of the driver.
-
-:c:func:`v4l2_async_nf_add_fwnode_remote` and
-:c:func:`v4l2_async_nf_add_i2c` are for bridge and ISP drivers for
-registering their async sub-devices with the notifier.
+notifier must be initialized using the :c:func:`v4l2_async_nf_init`.  Second,
+bridge drivers can then begin to form a list of subdevice descriptors that the
+bridge device needs for its operation. :c:func:`v4l2_async_nf_add_fwnode`,
+:c:func:`v4l2_async_nf_add_fwnode_remote` and :c:func:`v4l2_async_nf_add_i2c`
+are available for that purpose.
 
 Asynchronous sub-device registration helper for camera sensor drivers
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^