cmake: use compatible interface properties to disallow linking to a different version of SDL

Xcode/SDL/pkg-support/resources/CMake/sdl2-config.cmake

@@ -57,6 +57,8 @@ if(NOT TARGET SDL2::SDL2)
             INTERFACE_LINK_OPTIONS "SHELL:-F \"${SDL2_FRAMEWORK_PARENT_PATH}\";SHELL:-framework SDL2"
             COMPATIBLE_INTERFACE_BOOL "SDL2_SHARED"
             INTERFACE_SDL2_SHARED "ON"
+            COMPATIBLE_INTERFACE_STRING "SDL_VERSION"
+            INTERFACE_SDL_VERSION "SDL2"
     )
 endif()
 set(SDL2_SDL2_FOUND TRUE)