Update KDF documentation

Following the previous commits where we moved the KDF bridge into
provider side code, we need to update the documentation accordingly.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/12573)

doc/man3/EVP_PKEY_CTX_set1_pbe_pass.pod

@@ -42,10 +42,6 @@ supported by the algorithms that use them.
 
 =end comment
 
-=head1 NOTES
-
-All these functions are implemented as macros.
-
 =head1 RETURN VALUES
 
 All these functions return 1 for success and 0 or a negative value for failure.
@@ -58,6 +54,11 @@ L<EVP_PKEY_CTX_new(3)>,
 L<EVP_PKEY_CTX_ctrl_str(3)>,
 L<EVP_PKEY_derive(3)>
 
+=head1 HISTORY
+
+EVP_PKEY_CTX_set1_pbe_pass() was converted from a macro to a function in
+OpenSSL 3.0.
+
 =head1 COPYRIGHT
 
 Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.

doc/man3/EVP_PKEY_CTX_set_hkdf_md.pod

@@ -95,8 +95,6 @@ string which is converted to binary.
 
 =head1 NOTES
 
-All these functions are implemented as macros.
-
 A context for HKDF can be obtained by calling:
 
  EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
@@ -154,6 +152,11 @@ L<EVP_PKEY_CTX_new(3)>,
 L<EVP_PKEY_CTX_ctrl_str(3)>,
 L<EVP_PKEY_derive(3)>
 
+=head1 HISTORY
+
+All of the functions described here were converted from macros to functions in
+OpenSSL 3.0.
+
 =head1 COPYRIGHT
 
 Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.

doc/man3/EVP_PKEY_CTX_set_scrypt_N.pod

@@ -61,8 +61,6 @@ The scrypt KDF also uses EVP_PKEY_CTX_set1_pbe_pass() as well as
 the value from the string controls "pass" and "hexpass".
 See L<EVP_PKEY_CTX_set1_pbe_pass(3)>.
 
-All the functions described here are implemented as macros.
-
 =head1 RETURN VALUES
 
 All these functions return 1 for success and 0 or a negative value for
@@ -77,6 +75,11 @@ L<EVP_PKEY_CTX_new(3)>,
 L<EVP_PKEY_CTX_ctrl_str(3)>,
 L<EVP_PKEY_derive(3)>
 
+=head1 HISTORY
+
+All of the functions described here were converted from macros to functions in
+OpenSSL 3.0.
+
 =head1 COPYRIGHT
 
 Copyright 2017-2020 The OpenSSL Project Authors. All Rights Reserved.

doc/man3/EVP_PKEY_CTX_set_tls1_prf_md.pod

@@ -46,8 +46,6 @@ which is converted to binary.
 
 =head1 NOTES
 
-All these functions are implemented as macros.
-
 A context for the TLS PRF can be obtained by calling:
 
  EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_TLS1_PRF, NULL);
@@ -97,6 +95,11 @@ L<EVP_PKEY_CTX_new(3)>,
 L<EVP_PKEY_CTX_ctrl_str(3)>,
 L<EVP_PKEY_derive(3)>
 
+=head1 HISTORY
+
+All of the functions described here were converted from macros to functions in
+OpenSSL 3.0.
+
 =head1 COPYRIGHT
 
 Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.