fsl/board/ddr: optimize board-specific cpo for erratum A-009942

Optimize board-specific cpo for erratum A-009942 on b4860qds,
ls1043aqds, ls1043ardb, ls1046aqds, ls1046ardb, ls2080ardb,
t102xqds, t102xrdb, t1040qds, t104xrdb, t208xqds, t208xrdb,
t4qds, t4rdb boards.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/board/freescale/ls1046ardb/ddr.c b/board/freescale/ls1046ardb/ddr.c
index a9b7dbd..dd3b5d0 100644
--- a/board/freescale/ls1046ardb/ddr.c
+++ b/board/freescale/ls1046ardb/ddr.c
@@ -91,6 +91,9 @@
 	popts->ddr_cdr1 = DDR_CDR1_DHC_EN | DDR_CDR1_ODT(DDR_CDR_ODT_80ohm);
 	popts->ddr_cdr2 = DDR_CDR2_ODT(DDR_CDR_ODT_80ohm) |
 			  DDR_CDR2_VREF_TRAIN_EN | DDR_CDR2_VREF_RANGE_2;
+
+	/* optimize cpo for erratum A-009942 */
+	popts->cpo_sample = 0x70;
 }
 
 phys_size_t initdram(int board_type)