sstorage: Add missed header

PRI macro requires inttypes.h header

Signed-off-by: Ruslan Piasetskyi <ruslan.piasetskyi@gmail.com>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
diff --git a/secure_storage/ta/secure_storage_ta.c b/secure_storage/ta/secure_storage_ta.c
index 3ccc12d..8821d61 100644
--- a/secure_storage/ta/secure_storage_ta.c
+++ b/secure_storage/ta/secure_storage_ta.c
@@ -25,6 +25,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <inttypes.h>
 #include <secure_storage_ta.h>
 #include <tee_internal_api.h>
 #include <tee_internal_api_extensions.h>