ACPI / hotplug: Add .fixup() callback to struct acpi_hotplug_context

In order for the ACPI dock station code to be able to use the
callbacks pointed to by the ACPI device objects' hotplug contexts
add a .fixup() callback pointer to struct acpi_hotplug_context.
That callback will be useful to handle PCI devices located in
dock stations.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index db81412..4228c67 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -80,7 +80,7 @@
 		return NULL;
 
 	context->refcount = 1;
-	acpi_set_hp_context(adev, &context->hp, acpiphp_hotplug_event);
+	acpi_set_hp_context(adev, &context->hp, acpiphp_hotplug_event, NULL);
 	return context;
 }