drm/msm: Don't use a worker to capture fault devcoredump

Now that we use a threaded IRQ, it should be safe to do this in the
fault handler.

We can also remove fault_info from struct msm_gpu and just pass it
directly.

Signed-off-by: Connor Abbott <cwabbott0@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/654889/


Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>