i2c: i801: Instantiate SPD EEPROMs automatically

Call the function to instantiate SPD EEPROMs automatically on the
main SMBus controller.

Multiplexed SMBus systems are excluded for now as they are more
complex to handle.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>