SPM: Sort out tfm_secure_api.c file

- Rename 'tfm_utils.h' to 'utilities.h'.
- Rename 'tfm_spm_services_api.h'to 'tfm_spm_services.h'.
- Move 'tfm_secure_api.c' from spm/runtime to spm/model_func and
  sort out the content

Change-Id: Ie8831e2b1430eab6a2edc9b6c0487ef14f2fafc6
Signed-off-by: Summer Qin <summer.qin@arm.com>
diff --git a/secure_fw/spm/model_func/spm_func.c b/secure_fw/spm/model_func/spm_func.c
index 890e0b2..3d4491e 100644
--- a/secure_fw/spm/model_func/spm_func.c
+++ b/secure_fw/spm/model_func/spm_func.c
@@ -21,7 +21,7 @@
 #include "spm_db.h"
 #include "region_defs.h"
 #include "region.h"
-#include "tfm/tfm_spm_services_api.h"
+#include "tfm/tfm_spm_services.h"
 #include "tfm_spm_db_func.inc"
 
 #define EXC_RETURN_SECURE_FUNCTION 0xFFFFFFFD
@@ -38,7 +38,7 @@
  * This is the "Big Lock" on the secure side, to guarantee single entry
  * to SPE
  */
-extern int32_t tfm_secure_lock;
+static int32_t tfm_secure_lock;
 static int32_t tfm_secure_api_initializing = 1;
 
 static uint32_t *prepare_partition_iovec_ctx(