Deprecate hardware acceleration errors
Deprecate the module-specific XXX_HW_ACCEL_FAILED and
XXX_FEATURE_UNAVAILABLE errors, as alternative implementations should now
return `MBEDTLS_ERR_PLATFORM_HW_FAILED` and
`MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED`.
diff --git a/include/mbedtls/threading.h b/include/mbedtls/threading.h
index 75298bf..92e6e6b 100644
--- a/include/mbedtls/threading.h
+++ b/include/mbedtls/threading.h
@@ -36,7 +36,10 @@
extern "C" {
#endif
+/* MBEDTLS_ERR_THREADING_FEATURE_UNAVAILABLE is deprecated and should not be
+ * used. */
#define MBEDTLS_ERR_THREADING_FEATURE_UNAVAILABLE -0x001A /**< The selected feature is not available. */
+
#define MBEDTLS_ERR_THREADING_BAD_INPUT_DATA -0x001C /**< Bad input parameters to function. */
#define MBEDTLS_ERR_THREADING_MUTEX_ERROR -0x001E /**< Locking / unlocking / free failed with error code. */