Update crypto/fips to use generated rules, prereqs

This change preserves the same behavior and output as before, except that it
replaces the shell-based subdir-building recipe with generated rules and
prerequisites. This doesn't eliminate the recursive make, but refactors it so
that eliminating it will be more straightforward when the time comes.
Prefix fipsas.pl with FIPSCANISTERINTERNAL env var

This is in preparation for removing BUILDENV from Makefile.fips.
Remove BUILDENV from Makefile.fips
Remove parent path from FIPS_EX_OBJ.

This is part of a series of changes that will result in a broken build until
all of the changes are committed and squashed. The end goal will be a single,
large change that will "flip the switch" to a single-makefile-with-includes
build structure.
Remove soon-to-be-redundant top-level targets

This is part of a series of changes that will result in a broken build until
all of the changes are committed and squashed. The end goal will be a single,
large change that will "flip the switch" to a single-makefile-with-includes
build structure.