drm/amdkfd: Delete unnecessary unmap queue package submissions

drm/amdkfd: Delete unnecessary unmap queue package submissions

The previous way of using SDMA queue count to infer whether we should unmap
SDMA engines has bugs. The reason it did not cause issues is because MEC
firmware unmaps all queues (CP + SDMA) when a unmap package for compute
engine is received. Becasue of that, only one unmap queue package
is needed, instead of one unmap queue package for CP and each SDMA engine,
which results in much simpler driver code.

Signed-off-by: Yong Zhao <Yong.Zhao@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>