winsys/amdgpu: Make KMS handles valid for original DRM file descriptor
These changes fix https://bugs.freedesktop.org/110903 . They replace https://patchwork.freedesktop.org/series/62663/ and don't require any libdrm_amdgpu API changes anymore.
These changes fix https://bugs.freedesktop.org/110903 . They replace https://patchwork.freedesktop.org/series/62663/ and don't require any libdrm_amdgpu API changes anymore.