net/ethernet/atheros/atl1e/atl1e_main: Use module_pci_driver to register driver

Removing some boilerplate by using module_pci_driver instead of calling
register and unregister in the otherwise empty init/exit functions.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>