selftest: Avoid sstate corruption by calling cleansstate
Currently selftest doesn't use sstates because some tests
clean sstate cache; using sstates would give a performance
boost instead of building everything from scratch.
With this sstates are not corrupted using different methods
depending on tests:
devtool: These tests needed to delete the cache so SSTATE_DIR
as SSTATE_MIRRORS and set a temporal SSTATE_DIR.
sstatetests: This module already used a temporal SSTATE_DIR, so
just set up the SSTATE_MIRRORS.
Rest: Removed cleansstate, some of them required to force a
certain task, others were just removed or changed for another
task.
[YOCTO #10929]
Signed-off-by: Mariano Lopez <mariano.lopez@linux.intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
