sfc: Reduce delays in SFE4001 initialisation

Currently the board initialisation includes 2 delays of 1 second each.
Usually it is unnecessary to wait that long, so check before doing so.

Correct some of the comments and log messages while we're here.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>