drm/amdkfd: Set number of xgmi optimized SDMA engines for arcturus

some sdma engines are optimized for xgmi on arcturus.

Signed-off-by: Oak Zeng <[e-mail]>
Reviewed-by: Yong Zhao <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdkfd/kfd_device.c

···
 	.supports_cwsr = true,
 	.needs_iommu_device = false,
 	.needs_pci_atomics = false,
-	.num_sdma_engines = 8,
+	.num_sdma_engines = 2,
+	.num_xgmi_sdma_engines = 6,
 	.num_sdma_queues_per_engine = 8,
 };