skiboot/libmctp/ is a minimally modified version of upstream libmctp that is distributed with the openbmc project hosted at https://github.com/openbmc/libmctp.git This version is taken from libmctp.git commit 4df106db7766d ("astlpc: Add mctp_astlpc_tx_done() API") by copying most of files from the libmctp/ directory. The only modifications from the upstream source are the additions of this file, Makefile.inc which has been derived from the original Makefile.inc, astlpc.c (compilation error when MCTP_HAVE_FILEIO is undefined) and the removal of several unnecessary folders and files. Local libmctp changes should be kept to a minimum, and submitted upstream if possible.