cmake OPENSUBDIV_HAS_METAL examples

PixarAnimationStudios/OpenSubdiv opensubdiv/CMakeLists.txt :430 

target_compile_definitions(${osd_target} INTERFACE OPENSUBDIV_HAS_METAL)

lighttransport/tinyusdz src/osd/opensubdiv/CMakeLists.txt :402 

target_compile_definitions(${osd_target} INTERFACE OPENSUBDIV_HAS_METAL)