Add asn1 write tag and len to x509 use c config

Signed-off-by: Agathiyan Bragadeesh <agathiyan.bragadeesh2@arm.com>
diff --git a/include/mbedtls/asn1write.h b/include/mbedtls/asn1write.h
index 3c5072c..6fe57c8 100644
--- a/include/mbedtls/asn1write.h
+++ b/include/mbedtls/asn1write.h
@@ -48,6 +48,7 @@
 extern "C" {
 #endif
 
+#if defined(MBEDTLS_ASN1_WRITE_C) || defined(MBEDTLS_X509_USE_C)
 /**
  * \brief           Write a length field in ASN.1 format.
  *
@@ -76,7 +77,9 @@
  */
 int mbedtls_asn1_write_tag(unsigned char **p, const unsigned char *start,
                            unsigned char tag);
+#endif /* MBEDTLS_ASN1_WRITE_C || MBEDTLS_X509_USE_C */
 
+#if defined(MBEDTLS_ASN1_WRITE_C)
 /**
  * \brief           Write raw buffer data.
  *
@@ -393,4 +396,6 @@
 }
 #endif
 
+#endif /* MBEDTLS_ASN1_WRITE_C */
+
 #endif /* MBEDTLS_ASN1_WRITE_H */