[libata] pata_ali: Use IGN_SIMPLEX

Some ALi devices report simplex if they have been disabled and re-enabled, and
restoring the byte does not work. Ignore it - the needed supporting logic is
already present for the SATA ULi ports.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>