libata-acpi: add new hooks ata_acpi_dissociate() and ata_acpi_on_disable()

Add two hooks - ata_acpi_dissociate() which is called during driver
detach after the whole host is shutdown and ata_acpi_on_disable()
which is called when a device is disabled.

Signed-off-by: Tejun heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 8ae36ad..9e5fc5d 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -188,6 +188,21 @@
 }
 
 /**
+ * ata_acpi_dissociate - dissociate ATA host from ACPI objects
+ * @host: target ATA host
+ *
+ * This function is called during driver detach after the whole host
+ * is shut down.
+ *
+ * LOCKING:
+ * EH context.
+ */
+void ata_acpi_dissociate(struct ata_host *host)
+{
+	/* nada */
+}
+
+/**
  * ata_acpi_gtm - execute _GTM
  * @ap: target ATA port
  * @gtm: out parameter for _GTM result
@@ -716,3 +731,16 @@
 	dev->flags |= ATA_DFLAG_ACPI_FAILED;
 	return rc;
 }
+
+/**
+ * ata_acpi_on_disable - ATA ACPI hook called when a device is disabled
+ * @dev: target ATA device
+ *
+ * This function is called when @dev is about to be disabled.
+ *
+ * LOCKING:
+ * EH context.
+ */
+void ata_acpi_on_disable(struct ata_device *dev)
+{
+}