tg3: Add tg3_eee_pull_config() function

Add tg3_eee_pull_config() to pull the settings from the hardware and
populate the eee structure.

If Link Flap Avoidance is enabled, we pull the eee settings from the hw
so as not to cause a phy reset on eee config mismatch later. This
requires moving down tg3_setup_eee() below the tg3_pull_config() to not
trample existing settings.

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