ACPI: Remove acpi_start_single_object() and acpi_bus_start()

The ACPI PCI root bridge driver was the only ACPI driver implementing
the .start() callback, which isn't used by any ACPI drivers any more
now.

For this reason, acpi_start_single_object() has no purpose any more,
so remove it and all references to it.  Also remove
acpi_bus_start_device(), whose only purpose was to call
acpi_start_single_object().

Moreover, since after the removal of acpi_bus_start_device() the
only purpose of acpi_bus_start() remains to call
acpi_update_all_gpes(), move that into acpi_bus_add() and drop
acpi_bus_start() too, remove its header from acpi_bus.h and
update all of its former users accordingly.

This change was previously proposed in a different from by
Yinghai Lu.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>

drivers/pci/hotplug/acpiphp_glue.c

@@ -759,7 +759,6 @@ static int acpiphp_bus_add(struct acpiphp_func *func)
 			-ret_val);
 		goto acpiphp_bus_add_out;
 	}
-	ret_val = acpi_bus_start(device);
 
 acpiphp_bus_add_out:
 	return ret_val;
@@ -1148,8 +1147,7 @@ static void handle_bridge_insertion(acpi_handle handle, u32 type)
 		err("cannot add bridge to acpi list\n");
 		return;
 	}
-	if (!acpiphp_configure_bridge(handle) &&
-		!acpi_bus_start(device))
+	if (!acpiphp_configure_bridge(handle))
 		add_bridge(handle);
 	else
 		err("cannot configure and start bridge\n");

drivers/pci/hotplug/sgi_hotplug.c

@@ -457,8 +457,6 @@ static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
 					       ret, (int)(adr>>16),
 					       (int)(adr&0xffff));
 					/* try to continue on */
-				} else {
-					acpi_bus_start(device);
 				}
 			}
 		}