i2c: Let framebuffer drivers set their I2C bus class to DDC

Let framebuffer drivers set their I2C bus class to DDC. Once this is
done, we will be able to tell the eeprom driver to only probe for
EDID EEPROMs on these buses.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

drivers/video/fb_ddc.c

@@ -106,6 +106,7 @@ unsigned char *fb_ddc_read(struct i2c_adapter *adapter)
 	algo_data->setsda(algo_data->data, 1);
 	algo_data->setscl(algo_data->data, 1);
 
+	adapter->class |= I2C_CLASS_DDC;
 	return edid;
 }