Core: Change the type of ns_caller from int32_t/uint32_t to bool

ns_caller is a function input parameter that is used to indicate
if the caller comes from non-secure. Change the type of it from
int32_t/uint32_t to bool so that it will be better to indicate
the meaning.

Change-Id: I5ae16de7a80fe426b05efed24882113e9c28d95f
Signed-off-by: Summer Qin <summer.qin@arm.com>
diff --git a/secure_fw/spm/spm_api.h b/secure_fw/spm/spm_api.h
index 9d748bc..2fc18fc 100644
--- a/secure_fw/spm/spm_api.h
+++ b/secure_fw/spm/spm_api.h
@@ -658,7 +658,7 @@
  * \retval IPC_ERROR_BAD_PARAMETERS  Bad parameters input
  * \retval IPC_ERROR_MEMORY_CHECK    Check failed
  */
-int32_t tfm_memory_check(const void *buffer, size_t len, int32_t ns_caller,
+int32_t tfm_memory_check(const void *buffer, size_t len, bool ns_caller,
                          enum tfm_memory_access_e access,
                          uint32_t privileged);