drm/msm/a6xx: HFI v2 for A640 and A650

Add HFI v2 code paths required by Adreno 640 and 650 GPUs.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>