drm/radeon: rework the VM code a bit more (v2)

Roughly based on how nouveau is handling it. Instead of
adding the bo_va when the address is set add the bo_va
when the handle is opened, but set the address to zero
until userspace tells us where to place it.

This fixes another bunch of problems with glamor.

v2: agd5f: fix build after dropping patch 7/8.

Signed-off-by: Christian König <deathsimple@vodafone.de>

drivers/gpu/drm/radeon/radeon_object.c

@@ -52,7 +52,7 @@ void radeon_bo_clear_va(struct radeon_bo *bo)
 
 	list_for_each_entry_safe(bo_va, tmp, &bo->va, bo_list) {
 		/* remove from all vm address space */
-		radeon_vm_bo_rmv(bo->rdev, bo_va->vm, bo);
+		radeon_vm_bo_rmv(bo->rdev, bo_va);
 	}
 }