og to decouple the
Rx and Tx handling as much as possible to fit with the new I2C
binding model.  This change actually makes lirc_zilog a little more
broken than it already was - memory deallocation in particular got worse.
However, this change makes the remaining problems easier to see and address.

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>