USB: rio500: Remove Rio 500 kernel driver

The Rio500 kernel driver has not been used by Rio500 owners since 2001
not long after the rio500 project added support for a user-space USB stack
through the very first versions of usbdevfs and then libusb.

Support for the kernel driver was removed from the upstream utilities
in 2008:
943f624ab7

Cc: Cesar Miquel <miquel@df.uba.ar>
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/6251c17584d220472ce882a3d9c199c401a51a71.camel@hadess.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/Kconfig

@@ -47,16 +47,6 @@ config USB_SEVSEG
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbsevseg.
 
-config USB_RIO500
-	tristate "USB Diamond Rio500 support"
-	help
-	  Say Y here if you want to connect a USB Rio500 mp3 player to your
-	  computer's USB port. Please read <file:Documentation/usb/rio.rst>
-	  for more information.
-
-	  To compile this driver as a module, choose M here: the
-	  module will be called rio500.
-
 config USB_LEGOTOWER
 	tristate "USB Lego Infrared Tower support"
 	help