(maint) Fix issue with kernel letter casing in processors fact

This commit fixes an issue for GNU/kFreeBSD, HP-UX and AIX
where the processors structured fact couldn't properly resolve its
data. The kernel fact for these systems includes upper case characters
which were not accounted for in the original processors implementation.
Merge pull request #742 from whopper/processors-kernel-upcase

(maint) Fix issue with kernel letter casing in processors fact