Docs: install generic manpages to man section 7

Reviewed-by: Rich Salz <rsalz@openssl.org>

doc/crypto/crypto.pod

diff --git a/doc/crypto/crypto.pod b/doc/crypto/crypto.pod
index 819cc89..6ed3a90 100644
--- a/doc/crypto/crypto.pod
+++ b/doc/crypto/crypto.pod
@@ -1,5 +1,7 @@
 =pod
 
+=for comment openssl_manual_section:7
+
 =head1 NAME
 
 crypto - OpenSSL cryptographic library

doc/crypto/evp.pod

diff --git a/doc/crypto/evp.pod b/doc/crypto/evp.pod
index c930e7d..31f4590 100644
--- a/doc/crypto/evp.pod
+++ b/doc/crypto/evp.pod
@@ -1,5 +1,7 @@
 =pod
 
+=for comment openssl_manual_section:7
+
 =head1 NAME
 
 evp - high-level cryptographic functions

doc/ssl/ssl.pod

diff --git a/doc/ssl/ssl.pod b/doc/ssl/ssl.pod
index bc62489..589fc2d 100644
--- a/doc/ssl/ssl.pod
+++ b/doc/ssl/ssl.pod
@@ -1,5 +1,7 @@
 =pod
 
+=for comment openssl_manual_section:7
+
 =head1 NAME
 
 SSL - OpenSSL SSL/TLS library