drm/amdgpu/runpm: enable runpm on baco capable VI+ asics

drm/amdgpu/runpm: enable runpm on baco capable VI+ asics

Seems to work reliably on VI+ except for a few so enable runpm barring
those where baco for runtime power management is not supported.

[rajneesh] Picked https://patchwork.freedesktop.org/patch/335402/ to
enable runtime pm with baco for kfd. Also fixed a checkpatch warning and
added extra checks for VEGA20 and ARCTURUS.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>