USB: empeg: clean up and handle speeds

The empeg is pretty fixed. Tidy up the long foo->bar->baz stuff and
encode the fixed speed properly.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>