feat(imx8m): add the ddr frequency change support for imx8m family

Add the DDR frequency change support.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: If1167785796b8678c351569b83d2922c66f6e530
diff --git a/plat/imx/imx8m/imx8mp/platform.mk b/plat/imx/imx8m/imx8mp/platform.mk
index ded31ca..45f2972 100644
--- a/plat/imx/imx8m/imx8mp/platform.mk
+++ b/plat/imx/imx8m/imx8mp/platform.mk
@@ -16,7 +16,10 @@
 include drivers/arm/gic/v3/gicv3.mk
 
 IMX_DRAM_SOURCES	:=	plat/imx/imx8m/ddr/dram.c		\
-				plat/imx/imx8m/ddr/dram_retention.c
+				plat/imx/imx8m/ddr/clock.c		\
+				plat/imx/imx8m/ddr/dram_retention.c	\
+				plat/imx/imx8m/ddr/ddr4_dvfs.c		\
+				plat/imx/imx8m/ddr/lpddr4_dvfs.c
 
 IMX_GIC_SOURCES		:=	${GICV3_SOURCES}			\
 				plat/common/plat_gicv3.c		\