drm/amdgpu/gfx9: new queue policy, take first 2 queues of each pipe

Instead of taking the first pipe and giving the rest to kfd, take the
first 2 queues of each pipe.

Effectively, amdgpu and amdkfd own the same number of queues. But
because the queues are spread over multiple pipes the hardware will be
able to better handle concurrent compute workloads.

amdgpu goes from 1 pipe to 4 pipes, i.e. from 1 compute threads to 4
amdkfd goes from 3 pipe to 4 pipes, i.e. from 3 compute threads to 4

gfx9 was missed when this patch set was rebased to include gfx9.
Acked-by: Tom St Denis <tom.stdenis@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Andres Rodriguez <andresx7@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

@@ -873,8 +873,8 @@ static void gfx_v9_0_compute_queue_acquire(struct amdgpu_device *adev)
 		if (mec >= adev->gfx.mec.num_mec)
 			break;
 
-		/* policy: amdgpu owns all queues in the first pipe */
-		if (mec == 0 && pipe == 0)
+		/* policy: amdgpu owns the first two queues of the first MEC */
+		if (mec == 0 && queue < 2)
 			set_bit(i, adev->gfx.mec.queue_bitmap);
 	}