test/py: pass -v option when executing sandbox

This shows more output, such as the internal output generated by the unit
test ("ut") command, which makes it easier to debug issues.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed