ACPI: DPTF: Drop stale link from Kconfig help

The web site pointed to from the DPTF Kconfig help is not accessible
any more, so drop the link to it from there.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/dptf/Kconfig

@@ -11,9 +11,6 @@ menuconfig ACPI_DPTF
 	  a coordinated approach for different policies to effect the hardware
 	  state of a system.
 
-	  For more information see:
-	  <https://01.org/intel%C2%AE-dynamic-platform-and-thermal-framework-dptf-chromium-os/overview>
-
 if ACPI_DPTF
 
 config DPTF_POWER