crosperf: Setup CPU configuration based on 'cpu_usage'.

Based on dut_config['cpu_usage'] setup DUT to use
big or little cores only on ARM platform.

Ignore 'cpu_usage' if setup is invalid for targeted platform.
For example 'big_only" on Intel or ARM w/o big/little support.

BUG=chromium:966514
TEST=Unitest and local HW tests passed.

Cq-Depend: chromium:1778515
Change-Id: Ida457a1ceaf20c4dcbb8d40334a2423836999574
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/1783849
Reviewed-by: Caroline Tice <cmtice@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Tested-by: Denis Nikitin <denik@chromium.org>
2 files changed