generate enum xrt_input_name from macro
Nobody likes excessive C macros but this allows us to remove duplication such as u_pp_xrt_input_name
and makes it easier to add new XRT_INPUT without having to add them elsewhere too.
Nobody likes excessive C macros but this allows us to remove duplication such as u_pp_xrt_input_name
and makes it easier to add new XRT_INPUT without having to add them elsewhere too.