Revert "radv: disable VK_SUBGROUP_FEATURE_VOTE_BIT"

This reverts commit 647c2b90e96a9ab8571baf958a7c67c1e816911a. There was
one recently-introduced bug in ac for dvec3 loads, but the other test
failures were actually bugs in the tests. See
https://github.com/KhronosGroup/VK-GL-CTS/commit/9429e621c48848d224e35f30a1ae45a4a079922c

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
(cherry picked from commit ba94a00c7ce1514372bfe9b35c8e0c7fb8cd710e)