[BUG] stream_start_offset set incorrectly leading to av sync errors

[kv2019i]

Describe the bug
Branch from Linux SOF driver bug thesofproject/linux#4781

The FW is not reporting correct start offset, which leads to incorrect delay reporting by the SOF driver to application. This can lead to video playback failures with applications using ALSA delay reporting.

To Reproduce
Play a video with mplayer and native ALSA backend:

• e.g. video from https://www.photojoseph.com/tips/2021/3/29/updated-march-2021-downloadable-audiovideo-sync-tests-2398-24-25-2997-50-5994
• play to system speaker: "mplayer -ao alsa:device=hw=0.2 Audio_Video_Sync_23,98_HEVC_1080p-by_PhotoJoseph.mov"

Reproduction Rate
50%

Expected behavior
Video should play reliably with accurate AV sync with applications using ALSA snd_pcm_delay().

Impact
High

Environment
kernel: thesofproject/linux@66ee247 (sof-dev)
SOF: 6c18829 (SOF main)
platform: MTL
topoplogy: sof-mtl-rt713-l0-rt1316-l12.tplg

[kv2019i]

Potentially fixed by #8756
UPDATE: I still get super large delay values reported when I tested this today with the above PR cherry-picked. So cannot confirm this fix yet.

[RanderWang]

Potentially fixed by #8756 UPDATE: I still get super large delay values reported when I tested this today with the above PR cherry-picked. So cannot confirm this fix yet.

@kv2019i please help to review this PR: thesofproject/linux#4791, thanks

[kv2019i]

The FW part is merged, so let's close this and continue in thesofproject/linux#4781