sfc: don't use netif_info et al before net_device is registered

Using netif_info() before the net_device is registered results in ugly
messages like the following:
sfc 0000:01:00.1 (unnamed net_device) (uninitialized): Solarflare NIC detected
Therefore use pci_info() et al until net_device is registered.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>