usb: core: Kconfig: Improve USB authorization mode help

Update the default USB device authorization mode help text so that the
meaning of the option and it's available values are described more
accurately.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/linux-usb/CAMuHMdUy793gzDVR0jfNnx5TUdJ_2MKH5NPGSgHkytAhArtqmw@mail.gmail.com/
Signed-off-by: Niko Mauno <niko.mauno@vaisala.com>
Link: https://lore.kernel.org/r/20240213124518.20231-1-niko.mauno@vaisala.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/Kconfig

@@ -126,10 +126,20 @@ config USB_DEFAULT_AUTHORIZATION_MODE
 	  Select the default USB device authorization mode. Can be overridden
 	  with usbcore.authorized_default command line or module parameter.
 
-	  The available values have the following meanings:
-		0 is unauthorized for all devices
-		1 is authorized for all devices (default)
-		2 is authorized for internal devices
+	  This option allows you to choose whether USB devices that are
+	  connected to the system can be used by default, or if they are
+	  locked down.
 
-	  If the default value is too permissive but you are unsure which mode
-	  to use, say 2.
+	  With value 0 all connected USB devices with the exception of root
+	  hub require user space authorization before they can be used.
+
+	  With value 1 (default) no user space authorization is required to
+	  use connected USB devices.
+
+	  With value 2 all connected USB devices with exception of internal
+	  USB devices require user space authorization before they can be
+	  used. Note that in this mode the differentiation between internal
+	  and external USB devices relies on ACPI, and on systems without
+	  ACPI selecting value 2 is analogous to selecting value 0.
+
+	  If unsure, keep the default value.