Renaming the enum to avoid redeclaration error

- The enums "SECURE" and "NONSECURE" are common names and may
  conflict with implementation defines such as in CMSIS.
- Renamed the structure security_t to caller_security_t to
  make it more meaningful.

Signed-off-by: Gowtham Siddarth <gowtham.siddarth@arm.com>
diff --git a/api-tests/val/common/val.h b/api-tests/val/common/val.h
index 3b1a713..f2ccf7a 100644
--- a/api-tests/val/common/val.h
+++ b/api-tests/val/common/val.h
@@ -167,9 +167,9 @@
 
 /* enums */
 typedef enum {
-    NONSECURE = 0x0,
-    SECURE    = 0x1,
-} security_t;
+    CALLER_NONSECURE = 0x0,
+    CALLER_SECURE    = 0x1,
+} caller_security_t;
 
 typedef enum {
     TEST_ISOLATION_L1      = 0x1,
@@ -295,6 +295,6 @@
     uint8_t  status;
 } test_status_buffer_t;
 
-typedef int32_t (*client_test_t)(security_t caller);
+typedef int32_t (*client_test_t)(caller_security_t caller);
 typedef int32_t (*server_test_t)(void);
 #endif /* VAL_COMMON_H */