dm: sandbox: Enable systemace

Enable building the systemace code for sandbox. This increases build
coverage for sandbox.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/sandbox.h b/include/configs/sandbox.h
index 7127611..c51d4cd 100644
--- a/include/configs/sandbox.h
+++ b/include/configs/sandbox.h
@@ -211,4 +211,8 @@
 #define CONFIG_CMD_SATA
 #define CONFIG_SYS_SATA_MAX_DEVICE	2
 
+#define CONFIG_SYSTEMACE
+#define CONFIG_SYS_SYSTEMACE_WIDTH	16
+#define CONFIG_SYS_SYSTEMACE_BASE	0
+
 #endif