Its confusing to keep seeing sstate summary messages when hash equivalency is
active. This adds an option to control it. A default value is given which
maintains compatibility with different bitbake versions.
(From OE-Core rev: 038004866ff6650bcff7bb1bde36de6c0f451d29)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>