drm/radeon: fix bank tiling parameters on SI

The sixteen bank case wasn't handled here, leading to GPU
crashes because of userspace miscalculation.

Signed-off-by: Christian König <deathsimple@vodafone.de>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
1 file changed