[TG3]: Handle Sun onboard tg3 chips more correctly.

Get rid of all the SUN_570X logic and instead:

1) Make sure MEMARB_ENABLE is set when we probe the SRAM
   for config information.  If that is off we will get
   timeouts.

2) Always try to sync with the firmware, if there is no
   firmware running do not treat it as an error and instead
   just report it the first time we notice this condition.

3) If there is no valid SRAM signature, assume the device
   is onboard by setting TG3_FLAG_EEPROM_WRITE_PROT.

Update driver version and release date.

With help from Michael Chan and Fabio Massimo Di Nitto.

Signed-off-by: David S. Miller <davem@davemloft.net>