net: pasemi: Make pasemi_mac_init_module static

Fix sparse warning:

drivers/net/ethernet/pasemi/pasemi_mac.c:1842:5: warning:
 symbol 'pasemi_mac_init_module' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>