In continuation (and different) from this post -http://plugcomputer.org/plugforum/index.php?topic=28.0
I'v enabled I2c using GPIO pins that are multiplxed with SDIO interface.
1. Attached the patch
2. You need to make a cable that uses pin 6 as GND, pin 7 and SDCLK and pin8 as SDA -http://www.interfacebus.com/Secure_Digital_IO_Card_Pinout.html
3. In kernel 'make menuconfig' disable all SD/MCC stack and enable I2C GPIO -
The patch uses 5uSec delay, you can tweak it for your bus speed.