Core: Remove unused SVC number 'TFM_SVC_SCHEDULE'

tfm_thrd_activate_schedule() is only used in core, so won't trigger
SVC number 'TFM_SVC_SCHEDULE'.

Change-Id: I86a8fba34456058dc227df5b3c3dd7728dfc835a
Signed-off-by: Summer Qin <summer.qin@arm.com>
diff --git a/secure_fw/core/ipc/tfm_svcalls.c b/secure_fw/core/ipc/tfm_svcalls.c
index 301b508..e418159 100644
--- a/secure_fw/core/ipc/tfm_svcalls.c
+++ b/secure_fw/core/ipc/tfm_svcalls.c
@@ -1114,9 +1114,6 @@
 int32_t SVC_Handler_IPC(tfm_svc_number_t svc_num, uint32_t *ctx, uint32_t lr)
 {
     switch (svc_num) {
-    case TFM_SVC_SCHEDULE:
-        tfm_thrd_activate_schedule();
-        break;
     case TFM_SVC_EXIT_THRD:
         tfm_svcall_thrd_exit();
         break;
diff --git a/secure_fw/core/tfm_svc.h b/secure_fw/core/tfm_svc.h
index d52e3d3..418ce63 100644
--- a/secure_fw/core/tfm_svc.h
+++ b/secure_fw/core/tfm_svc.h
@@ -28,7 +28,6 @@
     TFM_SVC_PSA_EOI,
 #ifdef TFM_PSA_API
     TFM_SVC_IPC_REQUEST,
-    TFM_SVC_SCHEDULE,
     TFM_SVC_EXIT_THRD,
     /* PSA Client SVC */
     TFM_SVC_PSA_FRAMEWORK_VERSION,