drm/msm: expand trace to capture 15 data points per event

Current trace captures only first 2 data points per event,
Expand trace to captures first 15 data points per event
as many events have more than 2 data points.

CRs-Fixed: 2048612
Change-Id: Iec783f03ec2dae658b8586865fdec91194d107fe
Signed-off-by: Alan Kwong <akwong@codeaurora.org>