Added missing return codes to get_key_attributes

Note that PSA_ERROR_NOT_PERMITTED is not included
because I can't think of a scenario where you have
a valid key handle but aren't allowed to read the
attributes
diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 4742120..aa63396 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -1667,7 +1667,7 @@
  * \retval #PSA_ERROR_BAD_STATE
  *         The library has not been previously initialized by psa_crypto_init().
  *         It is implementation-dependent whether a failure to initialize
- *         results in this error code. 
+ *         results in this error code.
  */
 psa_status_t psa_cipher_decrypt(psa_key_handle_t handle,
                                 psa_algorithm_t alg,