Tell TF-A in EL3 about TEE message buffers.

This must be enabled by a flag in the manifest, as it won't work without
the matching support in TF-A, e.g. in the case of running tests on QEMU
without TF-A.

Bug: 132429380
Change-Id: I0a0848c7b1afb416d98c0afeabcc4601abf9d193
diff --git a/inc/hf/arch/tee.h b/inc/hf/arch/tee.h
index 709ad37..f37fe0b 100644
--- a/inc/hf/arch/tee.h
+++ b/inc/hf/arch/tee.h
@@ -18,4 +18,5 @@
 
 #include "hf/spci.h"
 
+void arch_tee_init(void);
 struct spci_value arch_tee_call(struct spci_value args);
diff --git a/inc/hf/manifest.h b/inc/hf/manifest.h
index f1aebaf..4c3c5dc 100644
--- a/inc/hf/manifest.h
+++ b/inc/hf/manifest.h
@@ -50,6 +50,7 @@
  * Hafnium manifest parsed from FDT.
  */
 struct manifest {
+	bool spci_tee_enabled;
 	spci_vm_count_t vm_count;
 	struct manifest_vm vm[MAX_VMS];
 };