[TG3]: Fix tg3_set_power_state()

Fix tg3_set_power_state to drive GPIOs properly based on the
TG3_FLAG_EEPROM_WRITE_PROTECT flag. Some delays are also added after D0
and D3 power state changes.

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