libata: migrate ACPI code over to new bindings

Now that we have the ability to directly glue the ACPI namespace to the
driver model in libata, we don't need the custom code to handle the same
thing. Remove it and migrate the functions over to the new code.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Holger Macht <holger@homac.de>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/pata_acpi.c

@@ -39,7 +39,7 @@ static int pacpi_pre_reset(struct ata_link *link, unsigned long deadline)
 {
 	struct ata_port *ap = link->ap;
 	struct pata_acpi *acpi = ap->private_data;
-	if (ap->acpi_handle == NULL || ata_acpi_gtm(ap, &acpi->gtm) < 0)
+	if (ata_ap_acpi_handle(ap) == NULL || ata_acpi_gtm(ap, &acpi->gtm) < 0)
 		return -ENODEV;
 
 	return ata_sff_prereset(link, deadline);
@@ -195,7 +195,7 @@ static int pacpi_port_start(struct ata_port *ap)
 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 	struct pata_acpi *acpi;
 
-	if (ap->acpi_handle == NULL)
+	if (ata_ap_acpi_handle(ap) == NULL)
 		return -ENODEV;
 
 	acpi = ap->private_data = devm_kzalloc(&pdev->dev, sizeof(struct pata_acpi), GFP_KERNEL);