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-at91/phy.c b/arch/arm/mach-at91/phy.c
index a10c0ca..6101eee 100644
--- a/arch/arm/mach-at91/phy.c
+++ b/arch/arm/mach-at91/phy.c
@@ -14,6 +14,7 @@
 #include <common.h>
 #include <asm/hardware.h>
 #include <asm/io.h>
+#include <linux/delay.h>
 #include <linux/sizes.h>
 #include <asm/arch/at91_rstc.h>
 #include <watchdog.h>