devel/llvm17: Welcome 17.0.1

Welcome the first release of LLVM 17. See the release announcement for
more details: https://discourse.llvm.org/t/llvm-17-0-1-released/73549

(Note that 17.0.0 was tagged, but contained an error so was not
released.)

Fix an issue where libffi would be linked if available by disabling it's
use in OpenMP. [0]

PR: 273801, 273947
Submitted by: Ivan Rozhuk <rozhuk.im@gmail.com> [0]