anv: Translate relative timeout to absolute when calling anv_timelines_wait
Fixes: 34f32a6d
The issue was found in !5005 (comment 498449)
There are no tests for this in VK-CTS, works with my small ad-hoc test - https://github.com/werman/VK-GL-CTS/commit/f2d1b995c2f01257ce2387e4fc736d38293fbc27