common: Drop linux/delay.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/ddr/marvell/axp/ddr3_write_leveling.c b/drivers/ddr/marvell/axp/ddr3_write_leveling.c
index 2061489..d4add44 100644
--- a/drivers/ddr/marvell/axp/ddr3_write_leveling.c
+++ b/drivers/ddr/marvell/axp/ddr3_write_leveling.c
@@ -10,6 +10,7 @@
 #include <asm/io.h>
 #include <asm/arch/cpu.h>
 #include <asm/arch/soc.h>
+#include <linux/delay.h>
 
 #include "ddr3_hw_training.h"