Change value of MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE

Change the value of the error MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE to
0x0023 to ensure the errors in the AES module are all in a continuous
range.
diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index 660ec2a..f1c3d3a 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -36,9 +36,12 @@
 #define MBEDTLS_AES_ENCRYPT     1
 #define MBEDTLS_AES_DECRYPT     0
 
+/* Error codes in range 0x0020-0x0022 */
 #define MBEDTLS_ERR_AES_INVALID_KEY_LENGTH                -0x0020  /**< Invalid key length. */
 #define MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH              -0x0022  /**< Invalid data input length. */
-#define MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE               -0x006E  /**< Feature not available, e.g. unsupported AES key size. */
+
+/* Error codes in range 0x0023-0x0023 */
+#define MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE               -0x0023  /**< Feature not available, e.g. unsupported AES key size. */
 
 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
     !defined(inline) && !defined(__cplusplus)
diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
index 8dfeb62..5fffb0d 100644
--- a/include/mbedtls/error.h
+++ b/include/mbedtls/error.h
@@ -52,7 +52,7 @@
  * GCM       2  0x0012-0x0014
  * BLOWFISH  2  0x0016-0x0018
  * THREADING 3  0x001A-0x001E
- * AES       2  0x0020-0x0022   0x006E-0x006E
+ * AES       2  0x0020-0x0022   0x0023-0x0023
  * CAMELLIA  2  0x0024-0x0026
  * XTEA      1  0x0028-0x0028
  * BASE64    2  0x002A-0x002C