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/md.h b/include/mbedtls/md.h
index bf29524..8bcf766 100644
--- a/include/mbedtls/md.h
+++ b/include/mbedtls/md.h
@@ -39,6 +39,8 @@
#define MBEDTLS_ERR_MD_BAD_INPUT_DATA -0x5100 /**< Bad input parameters to function. */
#define MBEDTLS_ERR_MD_ALLOC_FAILED -0x5180 /**< Failed to allocate memory. */
#define MBEDTLS_ERR_MD_FILE_IO_ERROR -0x5200 /**< Opening or reading of file failed. */
+
+/* MBEDTLS_ERR_MD_HW_ACCEL_FAILED is deprecated and should not be used. */
#define MBEDTLS_ERR_MD_HW_ACCEL_FAILED -0x5280 /**< MD hardware accelerator failed. */
#ifdef __cplusplus