drm/radeon/kms: fix r6xx/7xx 1D tiling CS checker v2

broken by:
drm/radeon/r600: fix tiling issues in CS checker.

v2: only apply it to 1D tiling case.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>