staging: most: core: replace struct most_inst_obj

This patch introduces struct interface_private as a replacement for
the struct most_inst_obj. This structure holds private data that is
only needed by the core module and will be accessed by a pointer from
within the most_interface structure. As a result of this replacement
the bus helper functions can be used to search for devices.
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/most/core.h

@@ -20,6 +20,7 @@
 #include <linux/device.h>
 
 struct module;
+struct interface_private;
 
 /**
  * Interface type
@@ -248,6 +249,7 @@ struct most_interface {
 						   unsigned char link_stat,
 						   unsigned char *mac_addr));
 	void *priv;
+	struct interface_private *p;
 };
 
 #define to_most_interface(d) container_of(d, struct most_interface, dev)