Staging: speakup: Clear hi font bit from attributes

Previously, speakup would see the hi-font bit in attributes.
Since this bit has nothing to do with attributes, we need to clear it.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>