ahci: jmb361 has only one port

JMB361 has only one port but reports it has two causing longish probe
failure on the second one.  Quirk it.

Reported by Gajo Petrovic in bz 10911.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Gajo Petrovic <gajo01@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>