Dynamic interface discovery (UARTs and maybe others)

[uraimo]

From here:

The names of these device files can vary wildly. I would suggest searching a list of possible serial device names.

Examples include:
ttyS
ttyAMA
ttymxc

Way better than the current static configuration.
This could be implemented for every board (the search order could not be necessarily the same for every board) or just for unknown boards.