tests/eas/rfc: defined the default CGroups for workload tasks execution
tests/eas/rfc: defined the default CGroups for workload tasks execution

Each time a workload generator task is executed ensure to execute it into
the specified default CGroup. If not default CGroup is specified the tasks
will be executed in the root control group.

Signed-off-by: Patrick Bellasi <431c86f368affbc3148c4669fbd465131f7e82cb@arm.com>

credp/lisa,joelagnel/lisa,joelagnel/lisa,arnoldlu/lisa,JaviMerino/lisa,mdigiorgio/lisa,credp/lisa,arnoldlu/lisa,credp/lisa,mdigiorgio/lisa,credp/lisa,ARM-software/lisa,ARM-software/lisa,bjackman/lisa,bjackman/lisa,ARM-software/lisa,ARM-software/lisa