driver/ddr/fsl: Add sync of refresh

Add sync of refresh for multiple DDR controllers. DDRC initialization
needs to complete first. Code is re-ordered to keep refresh close.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/drivers/ddr/fsl/main.c b/drivers/ddr/fsl/main.c
index f49939b..b72b242 100644
--- a/drivers/ddr/fsl/main.c
+++ b/drivers/ddr/fsl/main.c
@@ -692,6 +692,10 @@
 		}
 	}
 
+#ifdef CONFIG_FSL_DDR_SYNC_REFRESH
+	fsl_ddr_sync_memctl_refresh(first_ctrl, last_ctrl);
+#endif
+
 #ifdef CONFIG_PPC
 	/* program LAWs */
 	for (i = first_ctrl; i <= last_ctrl; i++) {