arm: atmel: add ddr2 initialization function

The MPDDRC supports different type of SDRAM
This patch add ddr2 initialization function

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/arch/arm/cpu/Makefile b/arch/arm/cpu/Makefile
index fd0da53..b2d30b1 100644
--- a/arch/arm/cpu/Makefile
+++ b/arch/arm/cpu/Makefile
@@ -1,2 +1,3 @@
+obj-$(CONFIG_AT91FAMILY) += at91-common/
 obj-$(CONFIG_TEGRA) += $(SOC)-common/
 obj-$(CONFIG_TEGRA) += tegra-common/