env: Move env_relocate() to env.h

Move env_relocate() over to the new header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/common/board_r.c b/common/board_r.c
index 84aec7f..99b1285 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -18,6 +18,7 @@
 #include <command.h>
 #include <console.h>
 #include <dm.h>
+#include <env.h>
 #include <environment.h>
 #include <fdtdec.h>
 #include <ide.h>