Expose mbedtls_error_to_psa_status for use in test drivers

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index edef287..7da2ff6 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -125,7 +125,7 @@
     if( global_data.initialized == 0 )  \
         return( PSA_ERROR_BAD_STATE );
 
-static psa_status_t mbedtls_to_psa_error( int ret )
+psa_status_t mbedtls_to_psa_error( int ret )
 {
     /* If there's both a high-level code and low-level code, dispatch on
      * the high-level code. */