media: staging: atomisp: Switch to use struct device_driver directly

In a preparation of split PCI glue driver from core part, convert
the driver to use more generic struct device_driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>