drivers/ieee802154/at86rf230: replace the code under _init and _exit by macro
drivers/ieee802154/at86rf230: replace the code under _init and _exit by macro

The code under _init and _exit functions is similar to the code of
module_spi_driver macro, which is a wrapper to the module_driver macro,
so use it instead.

Signed-off-by: Alexander Smirnov <143b7e387ad206693c5077db85b8df32630879d1@gmail.com>
Cc: Devendra Naga <80be44de42a8601c5f7021eac61c2116586290ae@gmail.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas