radeonsi: enable ARB_sparse_texture_clamp
Tested with: https://github.com/yuq/gfx/tree/master/base/gbm-surface-sparse-clamp
Khronos CTS failed tests:
KHR-GL46.sparse_texture_clamp_tests.SparseTextureClampLookupResidency
KHR-GL46.sparse_texture_clamp_tests.SparseTextureClampLookupColor
Both due to image load return all 0 for uncommitted region which is a HW limit for now.
Depends: !14362 (merged)
Edited by Qiang Yu