faft: firmware_ECThermal: Increase load of stress test.

Our new quantum CPU-powered devices can process 50 1MB blocks without
breaking a sweat. Rather than stressing based upon a fixed number of
blocks, instead stress with four threads for a fixed time (12 seconds).
Remove dead code for fixed-block stress testing.

TEST=Pass firmware_ECThermal on Peppy 10/10 tries.

Change-Id: I5dbdd860e376c99daa35ffd7a2cdbf1fee94b4dd
Reviewed-on: https://gerrit.chromium.org/gerrit/64691
Reviewed-by: Vic Yang <victoryang@chromium.org>
Commit-Queue: Shawn Nematbakhsh <shawnn@chromium.org>
Tested-by: Shawn Nematbakhsh <shawnn@chromium.org>
1 file changed