greybus: manifest: style fix missing space before '('

Checkpatch printed a style ERROR concerning a missing space before '('.
This patch fixes this issue.

Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>