env: Move env_set_ulong() to env.h

Move env_set_ulong() 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/board/BuR/common/br_resetc.c b/board/BuR/common/br_resetc.c
index c8cc73a..c0e7fb6 100644
--- a/board/BuR/common/br_resetc.c
+++ b/board/BuR/common/br_resetc.c
@@ -6,6 +6,7 @@
  * B&R Industrial Automation GmbH - http://www.br-automation.com/ *
  */
 #include <common.h>
+#include <env.h>
 #include <errno.h>
 #include <i2c.h>
 #include <dm/uclass.h>