usb-storage: make cypress_atacb a separate module

This patch (as1210) converts usb-storage's cypress_atacb 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 e6cc245..2c73fa9 100644
--- a/drivers/usb/storage/Kconfig
+++ b/drivers/usb/storage/Kconfig
@@ -146,7 +146,7 @@
 	  operation.
 
 config USB_STORAGE_CYPRESS_ATACB
-	bool "SAT emulation on Cypress USB/ATA Bridge with ATACB"
+	tristate "SAT emulation on Cypress USB/ATA Bridge with ATACB"
 	depends on USB_STORAGE
 	---help---
 	  Say Y here if you want to use SAT (ata pass through) on devices based
@@ -156,6 +156,8 @@
 	  If you say no here your device will still work with the standard usb
 	  mass storage class.
 
+	  If this driver is compiled as a module, it will be named ums-cypress.
+
 config USB_LIBUSUAL
 	bool "The shared table of common (or usual) storage devices"
 	depends on USB