esp32 hwcrypto: Make SHA-224 an obvious no-op for now

This is not the long term solution...

components/esp32/include/hwcrypto/sha.h

@@ -109,10 +109,6 @@ void esp_sha1_finish( SHA1_CTX *ctx, unsigned char output[20] );
  */
 void esp_sha1_output( const unsigned char *input, size_t ilen, unsigned char output[20] );
 
-///
-#define SHA256  SHA2_256
-#define SHA224  4 /* TODO: check this */
-
 /**
  * \brief          SHA-256 context structure
  */

components/esp32/include/rom/sha.h

@@ -37,7 +37,8 @@ enum SHA_TYPE {
     SHA1 = 0,
     SHA2_256,
     SHA2_384,
-    SHA2_512
+    SHA2_512,
+    SHA_INVALID = -1,
 };
 
 void ets_sha_init(SHA_CTX *ctx);