net: sunhme: Consolidate common probe tasks

Most of the second half of the PCI/SBUS probe functions are the same.
Consolidate them into a common function.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>