On startup determine the board_id based on the board name
passed from u-boot. This code also export "board" for use
by userland using sysenv.
Change-Id: I1064a49497c82b06f50d98650132bc0a7f543568
Modified the machine struct in include/minix/type.h to have an
additional field called board_id. This fields can be read out
by userland and drivers at runtime to enable automatic
configuration. The board_id field contains information about
the hardware architecture / board and such.
Change-Id: Ib12bc0d43fc9dbdb80ee0751c721ee516de1d2d6