[PATCH] sandbox: fix a compilation error

[Sergei Antonov]

With sandbox and sandbox64 configurations:

In file included from .../u-boot/include/test/test.h:156,
                 from .../u-boot/include/test/lib.h:9,
                 from .../u-boot/test/lib/test_crc8.c:8:
.../u-boot/arch/sandbox/include/asm/test.h: In function ‘sandbox_sdl_set_bpp’:
.../u-boot/arch/sandbox/include/asm/test.h:323:17: error: ‘ENOSYS’ undeclared (first use in this function)
  323 |         return -ENOSYS;
      |                 ^~~~~~

Cc: Tom Rini <trini at konsulko.com>
Cc: Simon Glass <sjg at chromium.org>
Signed-off-by: Sergei Antonov <saproj at gmail.com>
---
 arch/sandbox/include/asm/test.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
index e482271fe975..86968ea6d345 100644
--- a/arch/sandbox/include/asm/test.h
+++ b/arch/sandbox/include/asm/test.h
@@ -8,6 +8,7 @@
 #ifndef __ASM_TEST_H
 #define __ASM_TEST_H
 
+#include <errno.h>
 #include <video.h>
 #include <pci_ids.h>
 
-- 
2.37.2