platform/x86: toshiba_acpi: drop assignment of iio_info.driver_module

This is now handled by use of a macro for device registration.  The field
in iio_info will be going away shortly as it is no longer used.

Cc: <platform-driver-x86@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Azael Avalos <coproscefalo@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>