spi: butterfly: Switch to use module_parport_driver()

Switch to use module_parport_driver() to reduce boilerplate code.
Note, device_initcall() is a default for module_init().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210303091642.23929-3-andriy.shevchenko@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>