Partially revert "security/heimdal*: Remove LLVM_DEFAULT build prerequisite"

The suggested workaround will only work when autoreconf is not run.
The devel port still needs LLVM_DEFAULT while the non-devel port does
not

PR: 267814
Fixes: 22a683a337ef
MFH: 2022Q4

This partially reverts commit 22a683a337efe7169b61de8c9ec63e2c0d561891.