[Linaro:ARM_CI] Update to clang-17
I have halted merging this PR internally since it has been marked as draft. @elfringham Please let me know when it is ready to be merged.  @nitins17 It should be OK now thanks. It just needed a little tweak to get past configure.py when applied to a container with only clang-17 installed. Thanks, I'll resume the merge process internally. 
Update compiler in use to be clang-17 to
maintain sync with other builds.