Move OCSP ASN1 type functions to public header (#2239)

### Description of changes: 
Improve compatibility with OpenSSL APIs for OCSP.

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under the terms of the Apache 2.0 license and the ISC license.

Author: skmcgrail

crypto/ocsp/internal.h

@@ -234,7 +234,6 @@ struct ocsp_basic_response_st {
   STACK_OF(X509) *certs;
 };
 
-DECLARE_ASN1_FUNCTIONS(OCSP_ONEREQ)
 DECLARE_ASN1_FUNCTIONS(OCSP_RESPDATA)
 DECLARE_ASN1_FUNCTIONS(OCSP_REQINFO)
 DECLARE_ASN1_FUNCTIONS(OCSP_SIGNATURE)

include/openssl/ocsp.h

@@ -116,6 +116,7 @@ DECLARE_ASN1_FUNCTIONS(OCSP_RESPONSE)
 DECLARE_ASN1_FUNCTIONS(OCSP_CERTID)
 DECLARE_ASN1_FUNCTIONS(OCSP_REQUEST)
 DECLARE_ASN1_FUNCTIONS(OCSP_SINGLERESP)
+DECLARE_ASN1_FUNCTIONS(OCSP_ONEREQ)
 
 // d2i_OCSP_REQUEST_bio parses a DER-encoded OCSP request from |bp|, converts it
 // into an |OCSP_REQUEST|, and writes the result in |preq|.