Allow userspace to query for the tile mode array so userspace can properly
compute surface pitch and alignment requirement depending on tiling.

v2: Make strict aliasing safer by casting to char when copying
v3: merge fix from Christian
Signed-off-by: NJerome Glisse <jglisse@redhat.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>