The entry address for a VM is an IPA.

Change-Id: I9b447796789082c031c8a342a283d3050cf15ccb
diff --git a/inc/cpu.h b/inc/cpu.h
index d5bd29b..e949db7 100644
--- a/inc/cpu.h
+++ b/inc/cpu.h
@@ -5,6 +5,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "addr.h"
 #include "arch_cpu.h"
 #include "spinlock.h"
 
@@ -52,7 +53,7 @@
 size_t cpu_index(struct cpu *c);
 void cpu_irq_enable(struct cpu *c);
 void cpu_irq_disable(struct cpu *c);
-bool cpu_on(struct cpu *c, size_t entry, size_t arg);
+bool cpu_on(struct cpu *c, ipaddr_t entry, size_t arg);
 void cpu_off(struct cpu *c);
 struct cpu *cpu_find(size_t id);