The kfd_bo_list is used to restore process BOs after
evictions. As page tables could be destroyed during
evictions, we should also update pinned BOs' page tables
during restoring to make sure they are valid.

So for pinned BOs,
1, Validate them and update their page tables.
2, Don't add eviction fence for them.

v2:
 - Don't handle pinned ones specially in BO validation.(Felix)
Signed-off-by: Lang Yu <Lang.Yu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>