board: ti: am57xx: Update EMIF SDRAM 1 and 3 Timings

Update EMIF data based on recommendations from the now standard TI
EMIF tool version 1.1.1 based on 256MBx16 DDR3L Kingston D2516EC4BXGGB
data sheet

Update T_RRD from 5 to 6 based on AM57xx TRM -
Minimum number of DDR cycles from activate to ativate for a different
bank, minus 1.

Update T_CKESR from 4 to 3 based on AM57xx TRM - Minimum number of DDR
clocks cycles for which SDRAM must remain in self refresh, minus 1.

Signed-off-by: Schuyler Patton <spatton@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

board/ti/am57xx/board.c

@@ -131,9 +131,9 @@ static const struct emif_regs beagle_x15_emif2_ddr3_532mhz_emif_regs = {
 	.sdram_config2		= 0x08000000,
 	.ref_ctrl		= 0x000040F1,
 	.ref_ctrl_final		= 0x00001035,
-	.sdram_tim1		= 0xcccf36ab,
+	.sdram_tim1		= 0xcccf36b3,
 	.sdram_tim2		= 0x308f7fda,
-	.sdram_tim3		= 0x409f88a8,
+	.sdram_tim3		= 0x407f88a8,
 	.read_idle_ctrl		= 0x00050000,
 	.zq_config		= 0x5007190b,
 	.temp_alert_config	= 0x00000000,