block: introduce add_disk_fwnode()

Introduce add_disk_fwnode() as a replacement of device_add_disk() that
permits to pass and attach a fwnode to disk dev.

This variant can be useful for eMMC that might have the partition table
for the disk defined in DT. A parser can later make use of the attached
fwnode to parse the related table and init the hardcoded partition for
the disk.

device_add_disk() is converted to a simple wrapper of add_disk_fwnode()
with the fwnode entry set as NULL.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241002221306.4403-4-ansuelsmth@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>