feat(indirect message): add FFA_RXTX_MAP forwarding to SPMC

Hypervisor must forward FFA_RXTX_MAP ABI to SPMC, to allow it
to map RX/TX buffers in its stage 1 translation level.
Mailbox forwarding is needed for indirect messages with SPs, the SPMC
is in charge of message delivery when one of the two endpoints is an SP.

Change-Id: I3714a7203cb23cc3af7e613f3eb76c14648790ff
Signed-off-by: Federico Recanati <federico.recanati@arm.com>
diff --git a/src/arch/fake/hypervisor/ffa.c b/src/arch/fake/hypervisor/ffa.c
index f4bbd36..ab84b72 100644
--- a/src/arch/fake/hypervisor/ffa.c
+++ b/src/arch/fake/hypervisor/ffa.c
@@ -137,6 +137,11 @@
 	return false;
 }
 
+void plat_ffa_rxtx_map_forward(struct vm_locked vm_locked)
+{
+	(void)vm_locked;
+}
+
 ffa_partition_properties_t plat_ffa_partition_properties(
 	ffa_vm_id_t vm_id, const struct vm *target)
 {
@@ -229,6 +234,12 @@
 	return (struct vm_locked){.vm = NULL};
 }
 
+struct vm_locked plat_ffa_vm_find_locked_create(ffa_vm_id_t vm_id)
+{
+	(void)vm_id;
+	return (struct vm_locked){.vm = NULL};
+}
+
 bool plat_ffa_is_vm_id(ffa_vm_id_t vm_id)
 {
 	(void)vm_id;