Refactor -passin/-passout documentation

Always refer to openssl.pod instead of repeating the same description
everywhere.

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10126)
diff --git a/doc/man1/openssl-genrsa.pod b/doc/man1/openssl-genrsa.pod
index 39e221c..27ca9f7 100644
--- a/doc/man1/openssl-genrsa.pod
+++ b/doc/man1/openssl-genrsa.pod
@@ -52,7 +52,7 @@
 =item B<-passout> I<arg>
 
 The output file password source. For more information about the format
-see L<openssl(1)/Pass phrase options>.
+see L<openssl(1)/Pass Phrase Options>.
 
 =item B<-aes128>, B<-aes192>, B<-aes256>, B<-aria128>, B<-aria192>, B<-aria256>, B<-camellia128>, B<-camellia192>, B<-camellia256>, B<-des>, B<-des3>, B<-idea>