bitbake.conf: Exclude sstate-outputdirs flag from checksums
This was making deploy tasks MACHINE specific since they place output
into DEPLOY_DIR_IMAGE which contains MACHINE. On the plus side, this
was accidentally ensuring the output was placed for each machine,
on the downside it was triggering a rebuild every time for the different
checksum.
There is a better way to handle this which avoids the rebuild, see
the following tweak to do_deploy to mark it as MACHINE specific
in a different way.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
