IB/ipath: EEPROM support for 7220 devices, robustness improvements, cleanup

Add support for reading newer card's EEPROMs while continuing to support
older EEPROMs.

Also, add support for the temperature sensor if present.

Signed-off-by: Michael Albaugh <Michael.Albaugh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>