staging: speakup: migrate apollo, ltlk, audptr, decext, dectlk and spkout

This patch simply uses the changes introduced in previous patches and migrates
apollo, ltlk, audptr, decext, spkout and dectlk. Migrations are straightforward
function pointer updates.

Signed-off by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>