Driver/DDR: Moving Freescale DDR driver to a common driver

Freescale DDR driver has been used for mpc83xx, mpc85xx, mpc86xx SoCs.
The similar DDR controllers will be used for ARM-based SoCs.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/board/sbc8641d/Makefile b/board/sbc8641d/Makefile
index 9626b06..a9b2026 100644
--- a/board/sbc8641d/Makefile
+++ b/board/sbc8641d/Makefile
@@ -7,4 +7,4 @@
 
 obj-y	+= sbc8641d.o
 obj-y	+= law.o
-obj-$(CONFIG_FSL_DDR2) += ddr.o
+obj-$(CONFIG_SYS_FSL_DDR2) += ddr.o