Revert "kerberos: Fix numerous segfaults when using weak crypto"

This revision breaks Linux and MacOS cross builds because
TARGET_ENDIANNESS is not define during bootstrapping on these
platforms.

I think the correct approach would be to separate the new
fbsd_ossl_provider_load() and unload functions into their own
library (instead of libroken). This avoids the less desirable
option of including bsd.cpu.mk in secure/lib/Makefile.common,
which does build but could complicate future work.

Reported by: jrtc27

This reverts commit cb350ba7bf7ca7c4cb97ed2c20ab45af60382cfb.