Document no-sm2

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from openssl/openssl#6532)

INSTALL

@@ -548,9 +548,9 @@
                    Build without support for the specified algorithm, where
                    <alg> is one of: aria, bf, blake2, camellia, cast, chacha,
                    cmac, des, dh, dsa, ecdh, ecdsa, idea, md4, mdc2, ocb,
-                   poly1305, rc2, rc4, rmd160, scrypt, seed, siphash, sm3, sm4
-                   or whirlpool.  The "ripemd" algorithm is deprecated and if
-                   used is synonymous with rmd160.
+                   poly1305, rc2, rc4, rmd160, scrypt, seed, siphash, sm2, sm3,
+                   sm4 or whirlpool.  The "ripemd" algorithm is deprecated and
+                   if used is synonymous with rmd160.
 
   -Dxxx, -Ixxx, -Wp, -lxxx, -Lxxx, -Wl, -rpath, -R, -framework, -static
                    These system specific options will be recognised and