SPM: Add header files for partition static load

- Create two new header files that define the partition and service
  static data type.
- Create a header file for partition static loading definitions.

Change-Id: I73dafef7b587d3cad6fa35ff4788365a9936c062
Signed-off-by: Mingyang Sun <mingyang.sun@arm.com>
diff --git a/secure_fw/spm/cmsis_psa/tfm_thread.h b/secure_fw/spm/cmsis_psa/tfm_thread.h
index 8e96e3f..159344b 100644
--- a/secure_fw/spm/cmsis_psa/tfm_thread.h
+++ b/secure_fw/spm/cmsis_psa/tfm_thread.h
@@ -27,7 +27,9 @@
 /* Lower value has higher priority */
 #define THRD_PRIOR_MASK           0xFF
 #define THRD_PRIOR_HIGHEST        0x0
-#define THRD_PRIOR_MEDIUM         0x7F
+#define THRD_PRIOR_HIGH           0xF
+#define THRD_PRIOR_MEDIUM         0x1F
+#define THRD_PRIOR_LOW            0x7F
 #define THRD_PRIOR_LOWEST         0xFF
 
 /* Error code */