Update to man-refs.ent

[Warren Block]

On Sat, 14 Dec 2013, Steven Kreuzer wrote:

> Hello-
>
> If someone has some free time, would you be able to review this patch for me?
>
> http://clamps.exit2shell.com/~skreuzer/patches/nve-counter.patch
>
> It adds manual page entities for nvme(4), nvd(4), nvmecontrol(8) and
> counter(9) which are new for FreeBSD 10.

Looks good to me.  I can commit it, or you can, with an Approved from 
me.

Thanks!