pvr: fix sync waiting while using pvrsrvkm
pvrsrvkm type sync objects can have a pending state where,
the fence is unsignaled but does not have a valid sync file
due to not yet being submitted to kernel.
The wait function therefore needs to handle these types of syncs
through a spin loop.
This was seen as crashes in dEQP-VK.synchronization.timeline_semaphore.*
Signed-off-by: SoroushIMG <soroush.kashani@imgtec.com>
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22822>