Update documentation

Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
diff --git a/library/psa_crypto_core.h b/library/psa_crypto_core.h
index 694f682..610c69b 100644
--- a/library/psa_crypto_core.h
+++ b/library/psa_crypto_core.h
@@ -366,6 +366,9 @@
  *       entry point as defined in the PSA driver interface specification for
  *       transparent drivers.
  *
+ * \note This function will call the driver for psa_sign_hash
+ *       and go through driver dispatch again.
+ *
  * \param[in]  attributes       The attributes of the key to use for the
  *                              operation.
  * \param[in]  key_buffer       The buffer containing the key context.
@@ -406,6 +409,9 @@
  *       entry point as defined in the PSA driver interface specification for
  *       transparent drivers.
  *
+ * \note This function will call the driver for psa_verify_hash
+ *       and go through driver dispatch again.
+ *
  * \param[in]  attributes       The attributes of the key to use for the
  *                              operation.
  * \param[in]  key_buffer       The buffer containing the key context.