o Copy kb920x_machdep.c to at91_machdep.c
o Move board_init to new board_kb920x.c
o rename ramsize to at91_ramsize and make it accessible to board_* files.
o Delete files.kb920x. We can do this selection with the new boards.
o Add a stub for the tsc4370 board init, which will be added in
a future commit.
o Add new 'devices' at91_board_kb920x and at91_board_tsc4370. More are
needed and will be added in future commits.
Reviewed by: stass, cognet
