Compute the FIPS checksums in $(BLDDIR) and remove it from update target
Add also update-fips-checksums to update the checksums in the
$(SRCDIR) if the $(SRCDIR) and $(BLDDIR) is different.
The fips-checksums and generate_fips_sources targets are always
produced (regardless of enable-fips) as nothing else depends on them
and they are developer targets.
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15229)