Only build with Wayland if USE_WAYLAND_WSI is on.

CMakeLists.txt

@@ -188,10 +188,9 @@ if(UNIX AND NOT (APPLE OR ANDROID) AND VULKAN)
 	find_package(Wayland)
 	if(NOT WAYLAND_FOUND)
 		message(STATUS "Could not find Wayland libraries, disabling Wayland WSI support for Vulkan.")
-	else()
+	elseif(USE_WAYLAND_WSI)
 		include_directories(${WAYLAND_INCLUDE_DIR})
 		add_definitions(-DVK_USE_PLATFORM_WAYLAND_KHR)
-		add_definitions(-DUSE_WAYLAND_WSI=ON)
 	endif()
 
 	if(USE_VULKAN_DISPLAY_KHR)