Fix cmake install on iOS

Fixes:
INSTALL TARGETS given no BUNDLE DESTINATION for MACOSX_BUNDLE executable

cmake/install.cmake

@@ -30,7 +30,9 @@ endforeach()
 
 if (protobuf_BUILD_PROTOC_BINARIES)
   install(TARGETS protoc EXPORT protobuf-targets
-    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT protoc)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    BUNDLE DESTINATION ${CMAKE_INSTALL_BINDIR}
+    COMPONENT protoc)
   if (UNIX AND NOT APPLE)
     set_property(TARGET protoc
       PROPERTY INSTALL_RPATH "$ORIGIN/../${CMAKE_INSTALL_LIBDIR}")