[netdrvr] sfc: sfc: Add self-test support

Add a set of self-tests accessible thorugh ethtool.
Add hardware loopback and TX disable control code to support them.

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