Build: spec: mark -cts & -doc packages as noarch

First, -cts no longer contains lrmd_test (as of commit 088a5e7d4
enabling commit), and -doc was arch-specific since its introduction
in d24c1388d (which was only relatively shortly after rpm-4.8.0 came
out supporting noarch subpackages enabled as of 1d6ab4edc respective
commit) -- it just didn't get noticed for so long.