vf610: Add I2C support for Vybrid VF610 platform

This patch adds I2C support for Vybrid VF610 platform and adds
I2C0 support to VF610TWR board.

Signed-off-by: Alison Wang <b18965@freescale.com>
diff --git a/arch/arm/include/asm/arch-vf610/clock.h b/arch/arm/include/asm/arch-vf610/clock.h
index 04e418c..3cbae0b 100644
--- a/arch/arm/include/asm/arch-vf610/clock.h
+++ b/arch/arm/include/asm/arch-vf610/clock.h
@@ -29,6 +29,7 @@
 	MXC_UART_CLK,
 	MXC_ESDHC_CLK,
 	MXC_FEC_CLK,
+	MXC_I2C_CLK,
 };
 
 void enable_ocotp_clk(unsigned char enable);