platform/x86: topstar-laptop: revert "convert to module_acpi_driver()"

Revert commit
  15165594 ("topstar-laptop: convert to module_acpi_driver()")
to later add a platform device.

Signed-off-by: Guillaume Douézan-Grard <gdouezangrard@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>