Unrestore mbedtls_x509_string_to_names()

This function should be internal, being exposed only via functions like
mbedtls_x509write_crt_set_subject_name().

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/include/mbedtls/x509.h b/include/mbedtls/x509.h
index 1dde7af..7158555 100644
--- a/include/mbedtls/x509.h
+++ b/include/mbedtls/x509.h
@@ -322,8 +322,6 @@
  */
 int mbedtls_x509_dn_gets(char *buf, size_t size, const mbedtls_x509_name *dn);
 
-int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name);
-
 /**
  * \brief          Return the next relative DN in an X509 name.
  *
diff --git a/library/x509_internal.h b/library/x509_internal.h
index 8a2d2ed..09b6fc5 100644
--- a/library/x509_internal.h
+++ b/library/x509_internal.h
@@ -21,6 +21,7 @@
 #include "mbedtls/rsa.h"
 #endif
 
+int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name);
 int mbedtls_x509_get_name(unsigned char **p, const unsigned char *end,
                           mbedtls_x509_name *cur);
 int mbedtls_x509_get_alg_null(unsigned char **p, const unsigned char *end,