Core: Minimize the memory usage for service list

Split the rodata, data and bss of the service information.

Change-Id: I27b304dcde4220ebe106ba5ed8363da525ca351a
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 3edd8a8..99d35a2 100644
--- a/secure_fw/spm/spm_api.h
+++ b/secure_fw/spm/spm_api.h
@@ -136,7 +136,7 @@
 
 /* RoT Service data */
 struct tfm_spm_service_t {
-    struct tfm_spm_service_db_t service_db;  /* Service database pointer     */
+    const struct tfm_spm_service_db_t *service_db;/* Service database pointer */
     struct spm_partition_desc_t *partition;  /*
                                               * Point to secure partition
                                               * data