icd: Remove dead code from CMakeLists.txt
icd: Remove dead code from CMakeLists.txt

Change-Id: I6b60b2e71568a3a88a3366b04ab7cf911fa05526

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools