split out ioport related stuffs from vl.c into ioport.c.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/isa.h b/hw/isa.h
index a8c1a56..f126ecc 100644
--- a/hw/isa.h
+++ b/hw/isa.h
@@ -2,13 +2,9 @@
 #define HW_ISA_H
 /* ISA bus */
 
-extern target_phys_addr_t isa_mem_base;
+#include "ioport.h"
 
-int register_ioport_read(int start, int length, int size,
-                         IOPortReadFunc *func, void *opaque);
-int register_ioport_write(int start, int length, int size,
-                          IOPortWriteFunc *func, void *opaque);
-void isa_unassign_ioport(int start, int length);
+extern target_phys_addr_t isa_mem_base;
 
 void isa_mmio_init(target_phys_addr_t base, target_phys_addr_t size);