add port_yield from #10795 only on zephyr to fix #10822

[dhalbert]

-- Fixes #10822

Disables calls added to #10795 to port_yield(), except on zephyr port.

Thank you @daniel-alsen.

Tested on Metro ESP32-S3 to confirm it restores proper performance.

[FoamyGuy]

Looks good to me. restricts change to zephyr build only.

[dhalbert]

@tannewt if you have a more in-depth fix that is fine. I was just trying to reverse the effects on the change on the non-zephyr builds.

The original port_yield() was for #6742, which maybe is a different use for port_yield(). I think it might be good to figure out if portYIELD() is good enough, instead of adding a delay. I think it could also be done only on msec ticks instead of on every HOOK (RUN_BACKGROUND_TASKS) call, which is a lot more often. We can discuss.

[tannewt]

Sorry about this! We should definitely try FreeRTOS portYield. IIRC I added the time in order to get the idle task to run and reset its timer. There's gotta be another way to fix it though. We can do that in a follow up though.