doc: added missing closing doxygen brackets

boards/chronos/include/board.h

boards/msb-430-common/include/board-conf.h

boards/msba2/include/board.h

boards/pca10000/include/board.h

boards/redbee-econotag/include/board.h

cpu/cc2538/include/cc2538-uart.h

drivers/include/netdev/default.h

sys/include/fd.h

sys/include/tm.h

sys/net/include/socket_base.h

sys/net/include/tcp.h

sys/net/include/udp.h