imx: Use MXC_I2C_CLK in imx i2c driver

i2c didn't work on imx25 due to missing MXC_IPG_PERCLK. Now using
MXC_I2C_CLK on all imx systems using i2c.

Signed-off-by: Matthias Weisser <weisserm@arcor.de>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/cpu/arm1136/mx35/generic.c b/arch/arm/cpu/arm1136/mx35/generic.c
index ef65176..7dc1a8e 100644
--- a/arch/arm/cpu/arm1136/mx35/generic.c
+++ b/arch/arm/cpu/arm1136/mx35/generic.c
@@ -357,6 +357,7 @@
 	case MXC_IPG_CLK:
 		return get_ipg_clk();
 	case MXC_IPG_PERCLK:
+	case MXC_I2C_CLK:
 		return get_ipg_per_clk();
 	case MXC_UART_CLK:
 		return imx_get_uartclk();