colibri-imx6: use dynamic DDR calibration

Enable dynamic DDR calibration to have a reliable behavior on edge
temperatures conditions.

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
diff --git a/configs/colibri_imx6_defconfig b/configs/colibri_imx6_defconfig
index 62a207f..e9c11d7 100644
--- a/configs/colibri_imx6_defconfig
+++ b/configs/colibri_imx6_defconfig
@@ -10,6 +10,7 @@
 CONFIG_ENV_SIZE=0x2000
 CONFIG_ENV_OFFSET=0xFFFFDE00
 CONFIG_MX6DL=y
+CONFIG_MX6_DDRCAL=y
 CONFIG_TARGET_COLIBRI_IMX6=y
 CONFIG_SYS_I2C_MXC_I2C1=y
 CONFIG_SYS_I2C_MXC_I2C2=y