feat(imx8mm): enable dram retention suuport on imx8mm

Enable dram retention support on i.MX8MM.

Change-Id: I76ada615d386602e551d572ff4e60ee19bb8e418
Signed-off-by: Jacky Bai <ping.bai@nxp.com>
diff --git a/plat/imx/imx8m/imx8mm/include/platform_def.h b/plat/imx/imx8m/imx8mm/include/platform_def.h
index ed693b9..32044e0 100644
--- a/plat/imx/imx8m/imx8mm/include/platform_def.h
+++ b/plat/imx/imx8m/imx8mm/include/platform_def.h
@@ -105,6 +105,7 @@
 #define IMX_DDRC_BASE			U(0x3d400000)
 #define IMX_DDRPHY_BASE			U(0x3c000000)
 #define IMX_DDR_IPS_BASE		U(0x3d000000)
+#define IMX_DDR_IPS_SIZE		U(0x1800000)
 #define IMX_ROM_BASE			U(0x0)
 
 #define GPV_BASE			U(0x32000000)
@@ -146,6 +147,7 @@
 #define OCRAM_S_BASE			U(0x00180000)
 #define OCRAM_S_SIZE			U(0x8000)
 #define OCRAM_S_LIMIT			(OCRAM_S_BASE + OCRAM_S_SIZE)
+#define SAVED_DRAM_TIMING_BASE		OCRAM_S_BASE
 
 #define COUNTER_FREQUENCY		8000000 /* 8MHz */