Build: Update to IAR support

Cleaned up #ifdef in secure_fw/services/tfm_spm_db.inc.template
Moved "signals" member to front of spm_partition_runtime_data_t.
The suggestion to move the aggregate types to the front turned
out to be hard to make work for both PSA and non-PSA configs.

Moved REGION_DECLARE macros to new include file,
platform/include/region.h.

Cleaned up type cast in core_test_api.c

Change-Id: I5dce1e7c019d4d7e4c14dc79be5ee2b855ad4f9e
Signed-off-by: Thomas Tornblom <thomas.tornblom@iar.com>
diff --git a/secure_fw/spm/spm_api.h b/secure_fw/spm/spm_api.h
index 33118b1..b28cac7 100644
--- a/secure_fw/spm/spm_api.h
+++ b/secure_fw/spm/spm_api.h
@@ -88,8 +88,8 @@
  */
 struct spm_partition_runtime_data_t {
 #ifdef TFM_PSA_API
-    struct tfm_event_t signal_evnt;     /* Event signal                      */
     uint32_t signals;                   /* Service signals had been triggered*/
+    struct tfm_event_t signal_evnt;     /* Event signal                      */
     struct tfm_list_node_t service_list;/* Service list                      */
     struct tfm_core_thread_t sp_thrd;   /* Thread object                     */
     uint32_t assigned_signals;          /* All assigned signals              */