ahci: Add alternate identifier for the 88SE9172

commit 17c60c6b763cb5b83b0185e7d38d01d18e55a05a upstream.

This can also appear as 0x9192. Reported in bugzilla and confirmed with the
board documentation for these boards.

Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=42970
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>