As we are moving to multi-dtb and board detection, remove static board
config options, and introduce board probing instead.
Luton: This add single-binary support for the two MSCC luton-based
reference boards - pcb090 and pcb091. The SoC chip ID is used to
determine the board type.
Ocelot: This add single-binary support for the two MSCC ocelot-based
reference boards - pcb120 and pcb123. The PHY ids on specific ports
are used to determine the board type.
Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>