drm/radeon/cik: Add tiling mode index for 1D tiled depth/stencil surfaces

CIK uses a different index for 1D DST surfaces compared to SI.  Expose
the new index so libdrm_radeon can use it properly for userspace
drivers.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>