Needs ATPX rather than _PR3 for dGPU power control.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=202263


Reviewed-by: Jim Qu <Jim.Qu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org