When describing v3 crypt, be specific as to which rotor machine.

"Crypt is an exact implementation of Boris Hagelin's cryptographic
machine called the M-209 by the U. S. Army"
From the third edition manual, crypt(I).

Index: lib/libc/crypt/crypt.3
===================================================================
RCS file: /cvs/src/lib/libc/crypt/crypt.3,v
diff -u -p -r1.45 crypt.3
--- lib/libc/crypt/crypt.3	6 Apr 2015 20:49:41 -0000	1.45
+++ lib/libc/crypt/crypt.3	9 Jan 2025 02:58:47 -0000
@@ -125,7 +125,7 @@ on failure.
 .Xr getpass 3 ,
 .Xr passwd 5
 .Sh HISTORY
-A rotor-based
+A M-209 based
 .Fn crypt
 function appeared in
 .At v3 .