drm/amdkfd: Add debugfs support to KFD

This commit adds several debugfs entries for kfd:

kfd/hqds: dumps all HQDs on all GPUs for KFD-controlled compute and
    SDMA RLC queues

kfd/mqds: dumps all MQDs of all KFD processes on all GPUs

kfd/rls: dumps HWS runlists on all GPUs

Signed-off-by: Yong Zhao <yong.zhao@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>