BUILD: ssl: fix to build (again) with boringssl

Limitations:
. disable force-ssl/tls (need more work)
should be set earlier with SSL_CTX_new (SSL_CTX_set_ssl_version is removed)
. disable generate-certificates (need more work)
introduce SSL_NO_GENERATE_CERTIFICATES to disable generate-certificates.

Cleanup some #ifdef and type related to boringssl env.
diff --git a/include/proto/openssl-compat.h b/include/proto/openssl-compat.h
index 5a31f02..645c9b7 100644
--- a/include/proto/openssl-compat.h
+++ b/include/proto/openssl-compat.h
@@ -104,10 +104,12 @@
 	return 1;
 }
 
+#if (!defined OPENSSL_NO_OCSP)
 static inline const OCSP_CERTID *OCSP_SINGLERESP_get0_id(const OCSP_SINGLERESP *single)
 {
 	return single->certId;
 }
+#endif
 
 static inline pem_password_cb *SSL_CTX_get_default_passwd_cb(SSL_CTX *ctx)
 {
@@ -147,4 +149,13 @@
 #define __OPENSSL_110_CONST__
 #endif
 
+#ifdef OPENSSL_IS_BORINGSSL
+#define SSL_NO_GENERATE_CERTIFICATES
+
+static inline int EVP_PKEY_base_id(EVP_PKEY *pkey)
+{
+	return EVP_PKEY_type(pkey->type);
+}
+#endif
+
 #endif /* _PROTO_OPENSSL_COMPAT_H */