[PATCH] test: Add udevice declaration to avoid build error

[Simon Glass]

When including this file on a board other than sandbox (e.g by enabling
UNIT_TEST and CMD_SETEXPR) an results. Fix it by declaring struct udevice
first.

Signed-off-by: Simon Glass <sjg at chromium.org>
Reported-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---

 include/dm/test.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/dm/test.h b/include/dm/test.h
index fe1cc2e278c..59c51d6b30c 100644
--- a/include/dm/test.h
+++ b/include/dm/test.h
@@ -6,6 +6,8 @@
 #ifndef __DM_TEST_H
 #define __DM_TEST_H
 
+struct udevice;
+
 /**
  * struct dm_test_cdata - configuration data for test instance
  *
-- 
2.31.0.291.g576ba9dcdaf-goog