wusb: wusb-cbaf (CBA driver) sysfs ABI simplification

Simplify the sysfs ABI of the wusb-cbaf (Cable Based Association)
driver: use one value per file and cause the write of the CHID to
fetch the CDID (instead of requiring a separate read).

Update the example wusb-cbaf script to work with this revised ABI.

Signed-off-by: Felipe Zimmerle <felipe.zimmerle@indt.org.br>
Signed-off-by: David Vrabel <david.vrabel@csr.com>
diff --git a/drivers/usb/wusbcore/Kconfig b/drivers/usb/wusbcore/Kconfig
index add077e..4ea7669 100644
--- a/drivers/usb/wusbcore/Kconfig
+++ b/drivers/usb/wusbcore/Kconfig
@@ -15,3 +15,26 @@
 
           To compile this support select Y (built in). It is safe to
 	  select even if you don't have the hardware.
+
+config USB_WUSB_CBAF
+	tristate "Support WUSB Cable Based Association (CBA)"
+	depends on USB
+	help
+	  Some WUSB devices support Cable Based Association. It's used to
+	  enable the secure communication between the host and the
+	  device.
+
+	  Enable this option if your WUSB device must to be connected
+	  via wired USB before establishing a wireless link.
+
+	  It is safe to select even if you don't have a compatible
+	  hardware.
+
+config USB_WUSB_CBAF_DEBUG
+	bool "Enable CBA debug messages"
+	depends on USB_WUSB_CBAF
+	help
+	  Say Y here if you want the CBA to produce a bunch of debug messages
+	  to the system log. Select this if you are having a problem with
+	  CBA support and want to see more of what is going on.
+