libata: make gtf_filter per-dev

Add ->gtf_filter to ata_device and set it to ata_acpi_gtf_filter when
initializing ata_link.  This is to allow quirks which apply different
gtf filters.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index be8e262..823e630 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -118,6 +118,8 @@
 
 /* libata-acpi.c */
 #ifdef CONFIG_ATA_ACPI
+extern unsigned int ata_acpi_gtf_filter;
+
 extern void ata_acpi_associate_sata_port(struct ata_port *ap);
 extern void ata_acpi_associate(struct ata_host *host);
 extern void ata_acpi_dissociate(struct ata_host *host);