Add the NALLINO platform detection code including the PAD multiplexing
and the enable pin.

The gfplatddetect implements the Garz & Fricke specific platform
detection mechanism. It simply reads some GPIO pins that are pre defined
at the time of production to determine the board model and the board
revision.

The NALLINO implementation, however, is somewhat special. It uses the
same SoC pads for the display output. Thus it needs to define the
display pinctl as default.

When probed the gfplatdetect switches the pinctrl ("pfid") if available and
enables the optional enable-gpio pin. It reads the GPIO values, disables the
enable-gpio again and re-muxes the pinctl back to "default".

BCS 746-000095