test: Release board after tests complete

When a board is finished with, the lab may want to power it off, or
perform some other function. Add a new script which is called when tests
are complete.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Simon Glass <sjg@chromium.org>

test/py/u_boot_console_exec_attach.py

@@ -70,3 +70,13 @@ class ConsoleExecAttach(ConsoleBase):
             raise
 
         return s
+
+    def close(self):
+        super().close()
+
+        self.log.action('Releasing board')
+        args = [self.config.board_type, self.config.board_identity]
+        cmd = ['u-boot-test-release'] + args
+        runner = self.log.get_runner(cmd[0], sys.stdout)
+        runner.run(cmd)
+        runner.close()