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/egnite/ethernut5/ethernut5_pwrman.c b/board/egnite/ethernut5/ethernut5_pwrman.c
index 7dbb6e8..81f1abf 100644
--- a/board/egnite/ethernut5/ethernut5_pwrman.c
+++ b/board/egnite/ethernut5/ethernut5_pwrman.c
@@ -38,6 +38,7 @@
 #include <asm/arch/gpio.h>
 #include <asm/io.h>
 #include <i2c.h>
+#include <linux/delay.h>
 
 #include "ethernut5_pwrman.h"