drm/radeon: move and rename radeon_bo_va function

It doesn't really belong into the object functions,
also rename it to avoid collisions with struct radeon_bo_va.

Signed-off-by: Christian König <deathsimple@vodafone.de>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 55f17f9..8cca1d2 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -1846,6 +1846,8 @@
 			    struct ttm_mem_reg *mem);
 void radeon_vm_bo_invalidate(struct radeon_device *rdev,
 			     struct radeon_bo *bo);
+struct radeon_bo_va *radeon_vm_bo_find(struct radeon_vm *vm,
+				       struct radeon_bo *bo);
 int radeon_vm_bo_add(struct radeon_device *rdev,
 		     struct radeon_vm *vm,
 		     struct radeon_bo *bo,