ipack: Move IndustryPack out of hw/char/

Move the header defining an IPackBus and IPackDevice base class into
a new include/ directory and move their implementation and a
PCI-IndustryPack bridge out of hw/char/ directory into a new hw/ipack/.

Acked-by: Alberto Garcia <agarcia@igalia.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/hw/char/ipoctal232.c b/hw/char/ipoctal232.c
index 99bab4d..f9c388e 100644
--- a/hw/char/ipoctal232.c
+++ b/hw/char/ipoctal232.c
@@ -8,7 +8,7 @@
  * later version.
  */
 
-#include "ipack.h"
+#include "hw/ipack/ipack.h"
 #include "qemu/bitops.h"
 #include "sysemu/char.h"