board_f: Make relocation functions generic

This header file is used by three archs. It could be used by all of them
since relocation is a common function. Move it into a generic file.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/xtensa/lib/relocate.c b/arch/xtensa/lib/relocate.c
index 3f747ec..010c1b0 100644
--- a/arch/xtensa/lib/relocate.c
+++ b/arch/xtensa/lib/relocate.c
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
-#include <asm/relocate.h>
+#include <relocate.h>
 #include <asm/sections.h>
 #include <asm/string.h>