Revert "drm/amdkfd: only allow heavy-weight TLB flush on some ASICs for SVM too"

This reverts commit 36bf9321.

It causes SVM regressions on Vega10 with XNACK-ON. Just revert it
at the moment.

./kfdtest --gtest_filter=KFDSVMRangeTest.MigratePolicyTest
Signed-off-by: Lang Yu <Lang.Yu@amd.com>
Reviewed-by: Philip Yang<Philip.Yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1229,9 +1229,7 @@ svm_range_unmap_from_gpus(struct svm_range *prange, unsigned long start,
 			if (r)
 				break;
 		}
-
-		if (kfd_flush_tlb_after_unmap(pdd->dev))
-			kfd_flush_tlb(pdd, TLB_FLUSH_HEAVYWEIGHT);
+		kfd_flush_tlb(pdd, TLB_FLUSH_HEAVYWEIGHT);
 	}
 
 	return r;