drm/msm/a6xx: Add a name for the crashdumper buffer

Add a buffer object name for the a6xx crashdumper so it can be
seen with the changes introduced by 7799a98edd
("drm/msm: Add a name field for gem objects").

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>