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/board/Marvell/gplugd/gplugd.c b/board/Marvell/gplugd/gplugd.c
index 459b7ba..1e2f227 100644
--- a/board/Marvell/gplugd/gplugd.c
+++ b/board/Marvell/gplugd/gplugd.c
@@ -21,6 +21,7 @@
 #include <asm/gpio.h>
 #include <miiphy.h>
 #include <asm/mach-types.h>
+#include <linux/delay.h>
 
 #ifdef CONFIG_ARMADA100_FEC
 #include <net.h>