ABI: sysfs-driver-mlxreg-io: fix the what fields

The author of this file should be given an award for creativity:
the What: fields on this file technically fulfills the description
at README. Yet, the way it is, it can't be parsed on a script,
and if someone would try to do something like:

	grep hwmon*/jtag_enable

It wouldn't find anything.

Fix the What fields in a way that it can be parseable by a
script and other search tools.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>