sfc: SFT9001: Fix speed reporting in 1G PHY loopback

Instead of disabling AN in loopback, just prevent restarting AN and
override the speed in sft9001_get_settings().

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/sfc/mdio_10g.c
Simple merge

diff --cc drivers/net/sfc/tenxpress.c
Simple merge

diff --cc drivers/net/sfc/workarounds.h
Simple merge