drm/amdkfd: Improve multiple SDMA queues support per process

HWS does not support over-subscription and the scheduler can not internally
modify the engine. Driver needs to program the correct engine ID.

Fix the queue and engine selection to create queues on alternating SDMA
engines. This allows concurrent bi-directional DMA transfers in a process
that creates two SDMA queues.

Signed-off-by: shaoyun liu <shaoyun.liu@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>