platform/x86: pcengines-apuv2: Use static device properties

platform/x86: pcengines-apuv2: Use static device properties

Convert the PC Engines APUv2/v3 board driver to use software nodes
and static device properties for its on-board LEDs and front button.

This change replaces the legacy gpiod_lookup_table and platform_data
with a modern software node implementation, which allows the leds-gpio
and gpio-keys drivers to use the standard device properties API.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://patch.msgid.link/yaaegm5z2vtkl6ci5jpfnv42aywfjtoqw3bjgtli43ypask2r6@a7gg37rwkpx2
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>