sc92031: more useful banner in kernel log

The banner currently printed when loading the module is mostly useless.

Replace it with a more informative one, printed after probing the device.

Output format copied from 8139cp/8139too.

Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Signed-off-by: David S. Miller <davem@davemloft.net>