Implement SPCI_RXTX_MAP to replace hf_vm_configure.

Bug: 132421502
Change-Id: I699f412f5090dead6a4c0dbfdc12f40b5aa8fe20
diff --git a/inc/vmapi/hf/spci.h b/inc/vmapi/hf/spci.h
index fe8e7df..1c3ae01 100644
--- a/inc/vmapi/hf/spci.h
+++ b/inc/vmapi/hf/spci.h
@@ -73,6 +73,13 @@
 
 #define SPCI_SLEEP_INDEFINITE 0
 
+/**
+ * For use where the SPCI specification refers explicitly to '4K pages'. Not to
+ * be confused with PAGE_SIZE, which is the translation granule Hafnium is
+ * configured to use.
+ */
+#define SPCI_PAGE_SIZE 4096
+
 /* The maximum length possible for a single message. */
 #define SPCI_MSG_PAYLOAD_MAX HF_MAILBOX_SIZE