net: pch_gbe: Use module_pci_driver()

Make use of the module_pci_driver() macro to remove some needless
boilerplate code from the pch_gbe driver. This does have the side effect
of removing the print of the driver's version during probe, but this is
pretty useless information anyway - the version has changed only once
whilst the driver has been in mainline, despite many changes being made
to it before and since.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: David S. Miller <davem@davemloft.net>