tests/eas/generic: Pick schedutil/sched governor automatically
tests/eas/generic: Pick schedutil/sched governor automatically

EAS requires a scheduler-driven governor to function.

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