Pass mapped memory size to secondary VMs on boot in x0.

Bug: 117082339
Change-Id: I851669d79cbae67d0a99dabc026b0919ae4e9ed3
diff --git a/src/load.c b/src/load.c
index ef033a6..0f71770 100644
--- a/src/load.c
+++ b/src/load.c
@@ -348,7 +348,9 @@
 		dlog("Loaded with %u vcpus, entry at 0x%x\n", cpu,
 		     pa_addr(secondary_mem_begin));
 
-		vm_secondary_start_vcpu(vm, 0, secondary_entry, 0);
+		vm_secondary_start_vcpu(
+			vm, 0, secondary_entry,
+			pa_difference(secondary_mem_begin, secondary_mem_end));
 	}
 
 	/*