net: ieee802154: mrf24j40: Drop unneeded of_match_ptr()

Driver can be used in different environments and moreover, when compiled
with !OF, the compiler may issue a warning due to unused mrf24j40_of_match
variable. Hence drop unneeded of_match_ptr() call.

While at it, update headers block to reflect above changes.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210531132226.47081-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>