Handle VM availability messages

Add handling for the FF-A VM availability messages to libsp. Currently
this is only a skeleton implementation that calls an empty callback in
the SPs.

Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
Change-Id: I037f7a67121b7b02ceb1775baf4508abb9455fcd
diff --git a/deployments/protected-storage/env/commonsp/ps_sp.c b/deployments/protected-storage/env/commonsp/ps_sp.c
index c43bccb..f88477b 100644
--- a/deployments/protected-storage/env/commonsp/ps_sp.c
+++ b/deployments/protected-storage/env/commonsp/ps_sp.c
@@ -110,3 +110,19 @@
 {
 	(void)interrupt_id;
 }
+
+ffa_result ffa_vm_created_handler(uint16_t vm_id, uint64_t handle)
+{
+	(void)vm_id;
+	(void)handle;
+
+	return FFA_OK;
+}
+
+ffa_result ffa_vm_destroyed_handler(uint16_t vm_id, uint64_t handle)
+{
+	(void)vm_id;
+	(void)handle;
+
+	return FFA_OK;
+}