Makefile.inc1: Reinstate building sbin/md5 for BOOTSTRAP_ALL_TOOLS

The sha256 and sha512 binaries are used when building release images.
Bootstrapping them used to be gated on MK_BOOT, which wasn't quite right
but in practice worked, at least in our use cases downstream. Add back
bootstrapping sbin/md5 and its aliases for this purpose to fix building
release images on Linux and macOS.

Fixes:	f213da8 ("Makefile.inc1: Remove beri straggler")

Makefile.inc1

@@ -2594,6 +2594,11 @@ _basic_bootstrap_tools+=usr.bin/mkfifo
 # jot is needed for the mkimg tests
 _basic_bootstrap_tools+=usr.bin/jot
 
+.if defined(BOOTSTRAP_ALL_TOOLS)
+# sha256 and sha512 are used by release/ (and possibly others)
+_basic_bootstrap_tools+=sbin/md5
+.endif
+
 # tzsetup is needed as an install tool
 .if ${MK_ZONEINFO} != "no"
 _basic_bootstrap_tools+=usr.sbin/tzsetup