msm: kgsl: Always send fence sync the timestamp it expects

Fence sync seems to react badly when it gets a unexpected timestamp
on a timeline.  When a event expires always send the expected timestamp
even if the event expired because the context was destroyed.

Change-Id: Ic0dedbad770363a00257d62c4940f7743bc33060
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>