arm: pxa: colibri_pxa270: add optional i2c support

This is useful once Andrew's PXA I2C driver gets merged.
Signed-off-by: NMarcel Ziswiler <marcel@ziswiler.com>

include/configs/colibri_pxa270.h

@@ -59,6 +59,15 @@
 #define	CONFIG_CMD_MMC
 #define	CONFIG_CMD_USB
 
+/* I2C support */
+#ifdef CONFIG_SYS_I2C
+#define CONFIG_CMD_I2C
+#define CONFIG_SYS_I2C_PXA
+#define CONFIG_PXA_STD_I2C
+#define CONFIG_PXA_PWR_I2C
+#define CONFIG_SYS_I2C_SPEED		100000
+#endif
+
 /* LCD support */
 #ifdef CONFIG_LCD
 #define CONFIG_PXA_LCD