factory: tweak the DEPLOY_DIR variables for multiconfig
factory: tweak the DEPLOY_DIR variables for multiconfig

Trying again to make this work for multiconfig builds
while not munging the task hashes for non-mc builds, so
sstate can be shared.

There's still the problem that dependencies on image builds
have different task names in the mc vs non-mc setup, which
prevents the autobuilder-uses-mc/developers-don't sharing
mode from being workable.

madisongh/autobuilder