Documentation/features: Update feature lists for 6.1

Run the refresh script to document the recent feature additions
on loong, um and csky as of v6.1-rc7.

Signed-off-by: Wei Li <liwei391@huawei.com>
Link: https://lore.kernel.org/r/20221203093750.4145802-1-liwei391@huawei.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>