usb-storage: make isd200 a separate module

This patch (as1208) converts usb-storage's isd200 subdriver into a
separate module.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/storage/Kconfig b/drivers/usb/storage/Kconfig
index 7be8899f..fc356a7 100644
--- a/drivers/usb/storage/Kconfig
+++ b/drivers/usb/storage/Kconfig
@@ -46,7 +46,7 @@
 	  Freecom has a web page at <http://www.freecom.de/>.
 
 config USB_STORAGE_ISD200
-	bool "ISD-200 USB/ATA Bridge support"
+	tristate "ISD-200 USB/ATA Bridge support"
 	depends on USB_STORAGE
 	---help---
 	  Say Y here if you want to use USB Mass Store devices based
@@ -61,6 +61,8 @@
 	  - CyQ've CQ8060A CDRW drive
 	  - Planex eXtreme Drive RX-25HU USB-IDE cable (not model RX-25U)
 
+	  If this driver is compiled as a module, it will be named ums-isd200.
+
 config USB_STORAGE_USBAT
 	bool "USBAT/USBAT02-based storage support"
 	depends on USB_STORAGE