parport: Switch to use module_pci_driver() macro

Eliminate some boilerplate code by using module_pci_driver() instead of
init/exit, moving the salient bits from init into probe.

Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>