Staging: remove telephony drivers

We said we would wait until the 3.6 kernel release to remove these
drivers.  So we waited 6 months longer, that should be fine.

If anyone wants them back, it is trivial to revert these, but given that
I don't think they even build anymore, I doubt anyone will want them.

Cc: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>