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/cpu/sa1100/timer.c b/arch/arm/cpu/sa1100/timer.c
index f2cbee5..a5cdaf5 100644
--- a/arch/arm/cpu/sa1100/timer.c
+++ b/arch/arm/cpu/sa1100/timer.c
@@ -12,6 +12,7 @@
 #include <common.h>
 #include <SA-1100.h>
 #include <time.h>
+#include <linux/delay.h>
 
 static ulong get_timer_masked (void)
 {