usb: drop comment about 2 uhci drivers

Drop the ancient comment about 2 usb/uhci drivers since there are
no longer 2 of them.

Cc: Johan Hovold <johan@kernel.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/5f93d906-4f5c-2a78-c1c7-36cf07e94bcc@infradead.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/Kconfig

@@ -129,9 +129,6 @@ config USB_SERIAL_DIGI_ACCELEPORT
 	  parallel port on the USB 2 appears as a third serial port on Linux.
 	  The Digi Acceleport USB 8 is not yet supported by this driver.
 
-	  This driver works under SMP with the usb-uhci driver.  It does not
-	  work under SMP with the uhci driver.
-
 	  To compile this driver as a module, choose M here: the
 	  module will be called digi_acceleport.