radeon: add si tiling support v5

v2: Only writte tile index if flags for it is set
v3: Remove useless allow2d scanout flags
v4: Split radeon_drm.h update to its own patch
v5: update against lastest next tree for radeon

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>