There are a some workloads where interrupts do not
always get generated, and as a result the timestamp
work was not triggered often enough.
Queue timestamp expired work from adreno_waittimestamp(),
when the timestamp expires while we are not waiting.
It is possible in this case that no interrupt fired
because no processes were waiting.
Queue timestamp expired work when freememontimestamp
is called, which reduces the amount of memory
built up by applications that use this api often.