[TG3]: Fix SRAM access during tg3_init_one()

5700 and 5701 will not return correct SRAM data when the chip is in
D3hot power state. tg3_get_eeprom_hw_cfg() must first put the device
in D0 before reading SRAM.

Thanks to Thomas Chenault at Dell for noticing this problem.

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