Currently, there are a number of variables which are displayed by
default, enabled with -e all, and listed by --list, but which you can
not give to --enable/-e.

So you can enable CPU0c1 (in the bic array), but you can't enable C1 or
C1% (not in the bic array, but exists in sysfs).

This runs counter to both the documentation and user expectations, and
it's just not very user friendly.

As such, the mechanism used by --hide has been duplicated, and is now
also used by --enable, so we can handle unknown names gracefully.

Note: One impact of this is that truly unknown fields given to --enable
will no longer generate errors, they will be silently ignored, as --hide
does.
Signed-off-by: Zephaniah E. Loss-Cutler-Hull <zephaniah@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>