radeonsi: add missing initialization of registers

(random initial gfx10 commit:)
Fixes: 78cdf9a99f0 - amd/addrlib: add gfx10 support

Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5798>
2 files changed