driver/ddr/fsl: Adjust CAS to preamble override for emulator

On ZeBu emulator, CAS to preamble overrides need to be set to
satisfy the timing. This only impact platforms with CONFIG_EMU.

These should be set before MEM_EN is set.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/drivers/ddr/fsl/ctrl_regs.c b/drivers/ddr/fsl/ctrl_regs.c
index 03d7ff1..b3477f0 100644
--- a/drivers/ddr/fsl/ctrl_regs.c
+++ b/drivers/ddr/fsl/ctrl_regs.c
@@ -2372,7 +2372,11 @@
 #ifdef CONFIG_SYS_FSL_DDR_EMU
 	/* disble DDR training for emulator */
 	ddr->debug[2] = 0x00000400;
-	ddr->debug[4] = 0xff800000;
+	ddr->debug[4] = 0xff800800;
+	ddr->debug[5] = 0x08000800;
+	ddr->debug[6] = 0x08000800;
+	ddr->debug[7] = 0x08000800;
+	ddr->debug[8] = 0x08000800;
 #endif
 #ifdef CONFIG_SYS_FSL_ERRATUM_A004508
 	if ((ip_rev >= 0x40000) && (ip_rev < 0x40400))