mali_stats: Add support for CSF GPUs

Add support for CSF GPUs. The "hwcnt" performance counter API has been
deprecated and replaced with a new "prfcnt" API. This commit adds
support for the new API.

BUG=b:353445169
TEST=Tested on both CSF and JM Mali drivers.

Change-Id: If2ed6516c9e6d55ecbb1e3bf8bd14dcbada6010b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/drm-tests/+/5748768
Tested-by: Yu-Che Cheng <giver@chromium.org>
Reviewed-by: Dominik Behr <dbehr@chromium.org>
Reviewed-by: Yu-Che Cheng <giver@chromium.org>
Commit-Queue: Justin Green <greenjustin@google.com>
9 files changed