scripts: get_abi.pl: extend xref match to other types

Currently, there are "What:" symbols for more than just
/sys.

Extend the regex to also cover configfs, /proc /dev and /kvd
symbols.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a1c7e2b2c37ed6e111dfc8641deb37ed96375a63.1616668017.git.mchehab+huawei@kernel.org


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