add support for ED25519 signature scheme (#254)

* wolfhsm: add support for Ed25519 signature algorithm

* test: add ED25519 tests

* ed25519: add DMA crypto callback handlers

* ed25519: fix type mismatch between wolfHSM and wolfcrypt

* ed25519: DMA: map ASN_PARSE_E to BAD_FUNC_ARG

* ed25519: rename cache import/export functions

* ed25519: use const qualifier inside wh_Crypto_Ed25519SerializeKeyDer

* ed25519: use WH_ERROR* for wh functions and translate to wc errors in cbs

* ed25519: remove 0-sized padding

* ed25519: use macro constant instead of magic number for max ctx len

Author: rizlik

examples/posix/wh_posix_server/user_settings.h

@@ -99,6 +99,9 @@ extern "C" {
 /** Curve25519 Options */
 #define HAVE_CURVE25519
 
+/** Ed25519 Options */
+#define HAVE_ED25519
+
 /** DH and DHE Options */
 #define NO_DH
 #define HAVE_DH_DEFAULT_PARAMS