[PATCH v2] doc: add removal note for power empty poll API

[Pattan, Reshma]

> -----Original Message-----
> From: Thomas Monjalon <thomas at monjalon.net>
-- snip --
> > +Removal Note
> > +------------
> > +The experimental empty poll APIs will be removed from the library in
> > +a future DPDK release.
> 
> It looks common in this file to forget the empty line after a title, but please
> don't forget it.
> 

Good catch, this is addressed in v3 now .