Do not build CUDA support in hwloc when --without-cuda is specified

[jsquyres]

• Originally reported in OpenMPI builds with CUDA and OpenCL dependency even with --with-cuda=no option #4219
• Master PR to fix the issue: hwloc: do not build hwloc CUDA support if --without-cuda used (and also always disable hwloc GL and OpenCL support) #4245

Needs to be applied to v2.x and v3.0.x. It may be desirable to also apply this to v2.0.x. @jsquyres and @hppritcha will discuss.

[jsquyres]

@Mazay0 Thanks for reporting the original issue in #4219. This issue is to track applying the fix to all the release branches.

[jsquyres]

See #4257 for a follow-on commit that could be added to all these PRs.

[hppritcha]

this fix has been back ported to all relevant branches. closing.