ACPI: Replace ACPI device add_type field with a match_driver flag

After the removal of the second argument of acpi_bus_scan() there is
no difference between the ACPI_BUS_ADD_MATCH and ACPI_BUS_ADD_START
add types, so the add_type field in struct acpi_device may be
replaced with a single flag.  Do that calling the flag match_driver.

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>