doc: document the additional LMS self test description

Reviewed-by: Hugo Landau <hlandau@devever.net>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/25598)

doc/man7/OSSL_PROVIDER-FIPS.pod

diff --git a/doc/man7/OSSL_PROVIDER-FIPS.pod b/doc/man7/OSSL_PROVIDER-FIPS.pod
index e0f4dd5..d7871eb 100644
--- a/doc/man7/OSSL_PROVIDER-FIPS.pod
+++ b/doc/man7/OSSL_PROVIDER-FIPS.pod
@@ -385,6 +385,8 @@
 
 =item "EDDSA" (B<OSSL_SELF_TEST_DESC_SIGN_EDDSA>)
 
+=item "LMS" (B<OSSL_SELF_TEST_DESC_SIGN_LMS>)
+
 Signature tests used with the "KAT_Signature" type.
 
 =item "ECDH" (B<OSSL_SELF_TEST_DESC_KA_ECDH>)