Driver/DDR: Add Freescale DDR driver for ARM

Make PowerPC specific code conditional so ARM SoCs can reuse
this driver. Add DDR3 driver for ARM.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/drivers/ddr/fsl/Makefile b/drivers/ddr/fsl/Makefile
index a328b43..265204f 100644
--- a/drivers/ddr/fsl/Makefile
+++ b/drivers/ddr/fsl/Makefile
@@ -31,4 +31,4 @@
 obj-$(CONFIG_SYS_FSL_DDRC_GEN2)	+= mpc85xx_ddr_gen2.o
 obj-$(CONFIG_SYS_FSL_DDRC_GEN3)	+= mpc85xx_ddr_gen3.o
 obj-$(CONFIG_SYS_FSL_DDR_86XX)		+= mpc86xx_ddr.o
-obj-$(CONFIG_FSL_DDR_INTERACTIVE)	+= interactive.o
+obj-$(CONFIG_SYS_FSL_DDRC_ARM_GEN3)	+= arm_ddr_gen3.o