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/arch/arm/mach-imx/mx7ulp/scg.c b/arch/arm/mach-imx/mx7ulp/scg.c
index 6e34803..4c06655 100644
--- a/arch/arm/mach-imx/mx7ulp/scg.c
+++ b/arch/arm/mach-imx/mx7ulp/scg.c
@@ -11,6 +11,7 @@
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/pcc.h>
 #include <asm/arch/sys_proto.h>
+#include <linux/delay.h>
 
 scg_p scg1_regs = (scg_p)SCG1_RBASE;