Attest: Generalize boot satus handling

Introduce wrapper structure to simplify the handling of
boot status data.

Change-Id: I4fecbf2b346e4e773a898b6013c0b351bcf5beeb
Signed-off-by: Tamas Ban <tamas.ban@arm.com>
diff --git a/secure_fw/services/initial_attestation/attestation.h b/secure_fw/services/initial_attestation/attestation.h
index 404fb41..f73ed0f 100644
--- a/secure_fw/services/initial_attestation/attestation.h
+++ b/secure_fw/services/initial_attestation/attestation.h
@@ -10,6 +10,7 @@
 
 #include "psa_initial_attestation_api.h"
 #include "tfm_client.h"
+#include "bl2/include/tfm_boot_status.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -34,7 +35,9 @@
  * \return Returns error code as specified in \ref psa_attest_err_t
  */
 enum psa_attest_err_t
-attest_get_boot_data(uint8_t major_type, void *ptr, uint32_t len);
+attest_get_boot_data(uint8_t major_type,
+                     struct tfm_boot_data *boot_data,
+                     uint32_t len);
 
 /*!
  * \brief Get the ID of the caller thread.