platform: x86: get rid of a non-existent document

Changeset 163ede97a9 ("Documentation: platform: Delete x86-laptop-drivers.txt")
removed the x86-laptop-drivers.txt file, but forgot to update its
Kconfig.

Fixes: 163ede97a9 ("Documentation: platform: Delete x86-laptop-drivers.txt")
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

drivers/platform/x86/Kconfig

@@ -433,9 +433,6 @@ config COMPAL_LAPTOP
 	  It adds support for rfkill, Bluetooth, WLAN, LCD brightness, hwmon
 	  and battery charging level control.
 
-	  For a (possibly incomplete) list of supported laptops, please refer
-	  to: Documentation/platform/x86-laptop-drivers.txt
-
 config SONY_LAPTOP
 	tristate "Sony Laptop Extras"
 	depends on ACPI