feat(imx8m): update the ddr4 dvfs flow to include ddr3l support

the DDR3L & DDR4 can share same piece of code for DDR frequency scaling.
So update the ddr4 dvfs flow to support DDR3L too.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Anson Huang <anson.huang@nxp.com>
Change-Id: Ifc6981f05ed8a4e399adad97690197a9680f554d
diff --git a/plat/imx/imx8m/ddr/dram.c b/plat/imx/imx8m/ddr/dram.c
index 0b0a527..53605cd 100644
--- a/plat/imx/imx8m/ddr/dram.c
+++ b/plat/imx/imx8m/ddr/dram.c
@@ -163,8 +163,18 @@
 	if (rc != 0) {
 		panic();
 	}
-}
 
+	if (dram_info.dram_type == DDRC_LPDDR4 && current_fsp != 0x0) {
+		/* flush the L1/L2 cache */
+		dcsw_op_all(DCCSW);
+		lpddr4_swffc(&dram_info, dev_fsp, 0x0);
+		dev_fsp = (~dev_fsp) & 0x1;
+	} else if (current_fsp != 0x0) {
+		/* flush the L1/L2 cache */
+		dcsw_op_all(DCCSW);
+		ddr4_swffc(&dram_info, 0x0);
+	}
+}
 
 /*
  * For each freq return the following info:
@@ -248,7 +258,7 @@
 		if (dram_info.dram_type == DDRC_LPDDR4) {
 			lpddr4_swffc(&dram_info, dev_fsp, fsp_index);
 			dev_fsp = (~dev_fsp) & 0x1;
-		} else if (dram_info.dram_type == DDRC_DDR4) {
+		} else {
 			ddr4_swffc(&dram_info, fsp_index);
 		}