Fix doc for i2d/d2i private/public key

=head1 NAME

d2i_PrivateKey, d2i_AutoPrivateKey, i2d_PrivateKey,

d2i_PrivateKey, d2i_PublicKey, d2i_AutoPrivateKey,

i2d_PrivateKey, i2d_PublicKey,

d2i_PrivateKey_bio, d2i_PrivateKey_fp

- decode and encode functions for reading and saving EVP_PKEY structures

 EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **a, const unsigned char **pp,

                          long length);

 EVP_PKEY *d2i_PublicKey(int type, EVP_PKEY **a, const unsigned char **pp,

                         long length);

 EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **a, const unsigned char **pp,

                              long length);

 int i2d_PrivateKey(EVP_PKEY *a, unsigned char **pp);

 int i2d_PublicKey(EVP_PKEY *a, unsigned char **pp);

 EVP_PKEY *d2i_PrivateKey_bio(BIO *bp, EVP_PKEY **a);

 EVP_PKEY *d2i_PrivateKey_fp(FILE *fp, EVP_PKEY **a)

use any key specific format or PKCS#8 unencrypted PrivateKeyInfo format. The

B<type> parameter should be a public key algorithm constant such as

B<EVP_PKEY_RSA>. An error occurs if the decoded key does not match B<type>.

d2i_PublicKey() does the same for public keys.

d2i_AutoPrivateKey() is similar to d2i_PrivateKey() except it attempts to

automatically detect the private key format.

i2d_PrivateKey() encodes B<key>. It uses a key specific format or, if none is

defined for that key type, PKCS#8 unencrypted PrivateKeyInfo format.

i2d_PublicKey() does the same for public keys.

These functions are similar to the d2i_X509() functions; see L<d2i_X509(3)>.

d2i_POLICYQUALINFO,

d2i_PROXY_CERT_INFO_EXTENSION,

d2i_PROXY_POLICY,

d2i_PublicKey,

d2i_RSAPrivateKey,

d2i_RSAPrivateKey_bio,

d2i_RSAPrivateKey_fp,