buildroot

rfkill: remove package

The rfkill program has been incorporated to the util-linux package.

The new implementation is based upon, and backward compatible with, the
original rfkill from Johannes Berg and Marcel Holtmann.

Signed-off-by: Carlos Santos <casantos@datacom.ind.br>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>