ACPI: Add support for acpi_load_table/acpi_unload_table_id

Make acpi_load_table() available for use by removing it from the #ifdef
ACPI_FUTURE_USAGE.

Also add a new routine used to unload an ACPI table of a given type and "id" -
acpi_unload_table_id().  The implementation of this new routine was almost a
direct copy of existing routine acpi_unload_table() - only difference being
that it only removes a specific table id instead of ALL tables of a given
type.  The SN hotplug driver (sgi_hotplug.c) now uses both of these interfaces
to dynamically load and unload SSDT ACPI tables.

Also, a few other ACPI routines now used by the SN hotplug driver are exported
(since the driver can be a loadable module):

 acpi_ns_map_handle_to_node
 acpi_ns_convert_entry_to_handle
 acpi_ns_get_next_node

Signed-off-by: Aaron Young <ayoung@sgi.com>
Cc: Greg KH <greg@kroah.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/namespace/nsxfobj.c

@@ -48,6 +48,50 @@
 #define _COMPONENT          ACPI_NAMESPACE
 ACPI_MODULE_NAME("nsxfobj")
 
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_get_id
+ *
+ * PARAMETERS:  Handle          - Handle of object whose id is desired
+ *              ret_id          - Where the id will be placed
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: This routine returns the owner id associated with a handle
+ *
+ ******************************************************************************/
+acpi_status acpi_get_id(acpi_handle handle, acpi_owner_id * ret_id)
+{
+	struct acpi_namespace_node *node;
+	acpi_status status;
+
+	/* Parameter Validation */
+
+	if (!ret_id) {
+		return (AE_BAD_PARAMETER);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		return (status);
+	}
+
+	/* Convert and validate the handle */
+
+	node = acpi_ns_map_handle_to_node(handle);
+	if (!node) {
+		(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+		return (AE_BAD_PARAMETER);
+	}
+
+	*ret_id = node->owner_id;
+
+	status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	return (status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_id)
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_get_type