drm/amdkfd: enable heavy-weight TLB flush on Vega20

It is to meet the requirement for memory allocation
optimization on MI50.
Signed-off-by: Eric Huang <jinhuieric.huang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1419,7 +1419,8 @@ static int kfd_ioctl_free_memory_of_gpu(struct file *filep,
 static bool kfd_flush_tlb_after_unmap(struct kfd_dev *dev) {
 	return KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 2) ||
 	       (KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 1) &&
-	        dev->adev->sdma.instance[0].fw_version >= 18);
+	        dev->adev->sdma.instance[0].fw_version >= 18) ||
+	       KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 0);
 }
 
 static int kfd_ioctl_map_memory_to_gpu(struct file *filep,