FF-A: map normal world rx/tx buffers to the SPMC

The SPMC can receive an FF-A RXTX map request to register
the NWd Hypervisor or OS kernel rx/tx buffers. In the SPMC
this request comes from the physical FF-A interface.
The buffers are mapped non-secure in the SPMC S-EL2 Stage-1
translation regime.

Change-Id: I65947f081b55e125edfd81e5e540a09dc8f915d9
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/inc/hf/arch/mm.h b/inc/hf/arch/mm.h
index e8d74ed..1d6f841 100644
--- a/inc/hf/arch/mm.h
+++ b/inc/hf/arch/mm.h
@@ -13,6 +13,8 @@
 
 #include "hf/addr.h"
 
+#include "vmapi/hf/ffa.h"
+
 /*
  * A page table entry (PTE) will take one of the following forms:
  *
@@ -154,3 +156,8 @@
  * Initializes the arch specific memory management.
  */
 bool arch_mm_init(paddr_t table);
+
+/**
+ * Return the arch specific mm mode for send/recv pages of given VM ID.
+ */
+uint32_t arch_mm_extra_attributes_from_vm(ffa_vm_id_t id);