drm/amdgpu: fix parameter documentation for amdgpu_vm_free_pts

The function was modified without updating the documentation.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -961,8 +961,7 @@ int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
  * amdgpu_vm_free_pts - free PD/PT levels
  *
  * @adev: amdgpu device structure
- * @parent: PD/PT starting level to free
- * @level: level of parent structure
+ * @vm: amdgpu vm structure
  *
  * Free the page directory or page table level and all sub levels.
  */