SPM: Enable passing a parameter on thread start

This patch enables callers of thrd_start() to provide a parameter that
will be passed to the thread entry function.
Previously this parameter was hard-coded to be NULL.
This is needed for further SPM modifications.

Change-Id: I5e0d5278867d26bc79b39a8594c3d6ef0eb1e561
Signed-off-by: Chris Brand <chris.brand@cypress.com>
Signed-off-by: Bohdan Hunko <Bohdan.Hunko@infineon.com>
diff --git a/secure_fw/spm/ffm/backend_ipc.c b/secure_fw/spm/ffm/backend_ipc.c
index b727be1..305d508 100644
--- a/secure_fw/spm/ffm/backend_ipc.c
+++ b/secure_fw/spm/ffm/backend_ipc.c
@@ -208,7 +208,7 @@
     return PSA_SUCCESS;
 }
 
-extern void common_sfn_thread(void);
+extern void common_sfn_thread(void *param);
 
 /* Parameters are treated as assuredly */
 void backend_init_comp_assuredly(struct partition_t *p_pt,
@@ -255,7 +255,8 @@
 
     thrd_start(&p_pt->thrd,
                thrd_entry,
-               THRD_GENERAL_EXIT);
+               THRD_GENERAL_EXIT,
+               NULL);
 }
 
 uint32_t backend_system_run(void)