image: Fix FIT and vboot tests to exit sandbox correctly

When used with a device tree, sandbox now requires a 'reset' controller. Add
this to the device trees so that reset works and the tests can complete.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: 5010d98f (sandbox: Use the reset driver to handle reset)

test/image/test-fit.py

@@ -108,6 +108,10 @@ base_fdt = '''
         model = "Sandbox Verified Boot Test";
         compatible = "sandbox";
 
+	reset@0 {
+		compatible = "sandbox,reset";
+	};
+
 };
 '''
 

test/vboot/sandbox-u-boot.dts

@@ -4,4 +4,7 @@
 	model = "Sandbox Verified Boot Test";
 	compatible = "sandbox";
 
+	reset@0 {
+		compatible = "sandbox,reset";
+	};
 };