Don't override our previous frequency we used after parking, and avoid
continually spiking back to the efficient frequency for mostly idle
workloads. Trust our ability to autotune across a workload switch.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200322163225.28791-2-chris@chris-wilson.co.uk