msm: kgsl: Record the ringbuffer start of pipeline timestamp

We are only writing the ringbuffer start of pipeline timestamp for
internal commands that do not have a draw context associated which
happen rarely (if ever).  We should be recording the timestamp for
*ALL* commands so when something goes wrong we can get a fuller
idea of the timestamp picture for each ringbuffer.

Change-Id: Ic0dedbad6d99130e31cd8a06dfe025610e9157a8
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>