tg3: Pull the phy advertised speed and flow control settings on driver load

Normally on driver load, we set the default settings for speed and flow
control. However, if the default setting is not compatible with the current link
state, we would autonegotiate and cause a link flap. To avoid this, we
pull the current advertised settings into the config.

A second scenario is if a user changes the speed/duplex/fc settings when
the interface is down. In this case we must not pull the settings from
the phy and overwrite user settings. We avoid that by checking the
USER_CONFIGURED flag.

Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>