greybus: usb-gb: import a "buildable" version of the usb-gb.c driver

Based on Fabien's original driver, this version is converted (mostly) to
the new greybus operation apis.  Lots of things still to do, not the
least being hooking up proper responses...
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/Makefile

@@ -14,7 +14,8 @@ greybus-y :=	core.o		\
 		sdio-gb.o	\
 		uart-gb.o	\
 		battery-gb.o	\
-		vibrator-gb.o
+		vibrator-gb.o	\
+		usb-gb.o
 
 obj-m += greybus.o
 obj-m += es1-ap-usb.o

drivers/staging/greybus/protocol.c

@@ -193,11 +193,16 @@ bool gb_protocol_init(void)
 		pr_err("error initializing vibrator protocol\n");
 		ret = false;
 	}
+	if (!gb_usb_protocol_init()) {
+		pr_err("error initializing usb protocol\n");
+		ret = false;
+	}
 	return ret;
 }
 
 void gb_protocol_exit(void)
 {
+	gb_usb_protocol_exit();
 	gb_vibrator_protocol_exit();
 	gb_sdio_protocol_exit();
 	gb_uart_protocol_exit();

drivers/staging/greybus/protocol.h

@@ -67,6 +67,9 @@ extern void gb_sdio_protocol_exit(void);
 extern bool gb_vibrator_protocol_init(void);
 extern void gb_vibrator_protocol_exit(void);
 
+extern bool gb_usb_protocol_init(void);
+extern void gb_usb_protocol_exit(void);
+
 bool gb_protocol_init(void);
 void gb_protocol_exit(void);