use names instead of numbers where possible, also print a better message if no

use names instead of numbers where possible, also print a better message if no
keyboard is connected.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5173 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1