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/imgtec/malta/malta.c b/board/imgtec/malta/malta.c
index 80005ec..88a1a63 100644
--- a/board/imgtec/malta/malta.c
+++ b/board/imgtec/malta/malta.c
@@ -13,6 +13,7 @@
 #include <pci_gt64120.h>
 #include <pci_msc01.h>
 #include <rtc.h>
+#include <linux/delay.h>
 
 #include <asm/addrspace.h>
 #include <asm/io.h>