armv8/ls2080aqds: Update DDR settings for four chip-select case

When 4 chip-selects are used, vref should use range 1 and CDT uses 80 ohm,
and 2T timing is enabled.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/board/freescale/ls2080aqds/ddr.c b/board/freescale/ls2080aqds/ddr.c
index ae681de..7e67ee0 100644
--- a/board/freescale/ls2080aqds/ddr.c
+++ b/board/freescale/ls2080aqds/ddr.c
@@ -134,10 +134,18 @@
 	popts->zq_en = 1;
 
 	if (ddr_freq < 2350) {
-		popts->ddr_cdr1 = DDR_CDR1_DHC_EN |
-				  DDR_CDR1_ODT(DDR_CDR_ODT_60ohm);
-		popts->ddr_cdr2 = DDR_CDR2_ODT(DDR_CDR_ODT_60ohm) |
-				  DDR_CDR2_VREF_RANGE_2;
+		if (pdimm[0].n_ranks == 2 && pdimm[1].n_ranks == 2) {
+			/* four chip-selects */
+			popts->ddr_cdr1 = DDR_CDR1_DHC_EN |
+					  DDR_CDR1_ODT(DDR_CDR_ODT_80ohm);
+			popts->ddr_cdr2 = DDR_CDR2_ODT(DDR_CDR_ODT_80ohm);
+			popts->twot_en = 1; /* enable 2T timing */
+		} else {
+			popts->ddr_cdr1 = DDR_CDR1_DHC_EN |
+					  DDR_CDR1_ODT(DDR_CDR_ODT_60ohm);
+			popts->ddr_cdr2 = DDR_CDR2_ODT(DDR_CDR_ODT_60ohm) |
+					  DDR_CDR2_VREF_RANGE_2;
+		}
 	} else {
 		popts->ddr_cdr1 = DDR_CDR1_DHC_EN |
 				  DDR_CDR1_ODT(DDR_CDR_ODT_100ohm);