radv: Use LDS for closest-hit hit attributes

radv: Use LDS for closest-hit hit attributes

Q2RTX: 23.1ms -> 22.9ms

shader-db:
Totals from 19 (0.69% of 2764) affected shaders:

MaxWaves: 197 -> 208 (+5.58%)
Instrs: 87702 -> 87817 (+0.13%); split: -0.03%, +0.16%
CodeSize: 474320 -> 475128 (+0.17%)
VGPRs: 1840 -> 1728 (-6.09%)
Latency: 2771599 -> 2773173 (+0.06%); split: -0.13%, +0.18%
InvThroughput: 561281 -> 533010 (-5.04%); split: -5.16%, +0.12%
VClause: 2782 -> 2788 (+0.22%); split: -0.18%, +0.40%
Copies: 12115 -> 12136 (+0.17%); split: -0.45%, +0.63%
Branches: 4116 -> 4122 (+0.15%)
PreVGPRs: 1665 -> 1638 (-1.62%); split: -1.92%, +0.30%
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21635>