demos: Fix CMake file to allow WSI selection

Define DEMOS_WSI_SELECTION CMake variable so it can be set
from CMake command line or GUI.

Change-Id: If2531d102fe9b054a1eee4da28431779b173fc10

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 60eef88817235b8993470dd986678c14997a4ae7..27ab6e50734a88f9a96e4c25be1845846a910dad 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,7 +21,7 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
     option(BUILD_WSI_XLIB_SUPPORT "Build Xlib WSI support" ON)
     option(BUILD_WSI_WAYLAND_SUPPORT "Build Wayland WSI support" ON)
     option(BUILD_WSI_MIR_SUPPORT "Build Mir WSI support" ON)
-    set(DEMOS_WSI_SELECTION XCB)
+    set(DEMOS_WSI_SELECTION "XCB" CACHE STRING "Select WSI target for demos")
 
     if (BUILD_WSI_XCB_SUPPORT)
         find_package(XCB REQUIRED)