powerpc/c29xpcie: modify DDR parameter to make DDR more stable

DDR parameters clk_adjust were changed. This can make the DDR
run more stable. The new value were gotten by the DDR testing
tool.

Signed-off-by: Po Liu <Po.Liu@freescale.com>

board/freescale/c29xpcie/ddr.c

@@ -62,7 +62,7 @@ void fsl_ddr_board_options(memctl_options_t *popts,
 				unsigned int ctrl_num)
 {
 	int i;
-	popts->clk_adjust = 2;
+	popts->clk_adjust = 4;
 	popts->cpo_override = 0x1f;
 	popts->write_data_delay = 4;
 	popts->half_strength_driver_enable = 1;