i2c: Add i2c_new_dummy() utility

This adds a i2c_new_dummy() primitive to help work with devices
that consume multiple addresses, which include many I2C eeproms
and at least one RTC.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 731928a..76014f8 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -259,6 +259,12 @@
 		      struct i2c_board_info *info,
 		      unsigned short const *addr_list);
 
+/* For devices that use several addresses, use i2c_new_dummy() to make
+ * client handles for the extra addresses.
+ */
+extern struct i2c_client *
+i2c_new_dummy(struct i2c_adapter *adap, u16 address, const char *type);
+
 extern void i2c_unregister_device(struct i2c_client *);
 
 /* Mainboard arch_initcall() code should register all its I2C devices.