ddr: Remove <common.h> and add needed includes

Remove <common.h> from this driver directory and when needed
add missing include files directly.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/ddr/fsl/ctrl_regs.c b/drivers/ddr/fsl/ctrl_regs.c
index 8f8c2c8..9a25192 100644
--- a/drivers/ddr/fsl/ctrl_regs.c
+++ b/drivers/ddr/fsl/ctrl_regs.c
@@ -10,12 +10,13 @@
  * Author: James Yang [at freescale.com]
  */
 
-#include <common.h>
+#include <config.h>
 #include <fsl_ddr_sdram.h>
 #include <fsl_errata.h>
 #include <fsl_ddr.h>
 #include <fsl_immap.h>
 #include <log.h>
+#include <linux/string.h>
 #include <asm/bitops.h>
 #include <asm/io.h>
 #if defined(CONFIG_FSL_LSCH2) || defined(CONFIG_FSL_LSCH3) || \