omap mailbox: fix empty struct device for omap_mbox

Since "mbox->dev" doesn't exist and isn't created either at
registration, this patch will create "struct device", which belongs to
"omap-mailbox" class and set this pointer for the member of
"struct omap_mbox".

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>

diff --git a/arch/arm/plat-omap/include/mach/mailbox.h b/arch/arm/plat-omap/include/mach/mailbox.h
index 7cbed93..577db68 100644
--- a/arch/arm/plat-omap/include/mach/mailbox.h
+++ b/arch/arm/plat-omap/include/mach/mailbox.h
@@ -53,7 +53,7 @@
 
 	mbox_msg_t		seq_snd, seq_rcv;
 
-	struct device		dev;
+	struct device		*dev;
 
 	struct omap_mbox	*next;
 	void			*priv;
@@ -67,7 +67,7 @@
 struct omap_mbox *omap_mbox_get(const char *);
 void omap_mbox_put(struct omap_mbox *);
 
-int omap_mbox_register(struct omap_mbox *);
+int omap_mbox_register(struct device *parent, struct omap_mbox *);
 int omap_mbox_unregister(struct omap_mbox *);
 
 #endif /* MAILBOX_H */