leds: apu: drop obsolete support for apu>=2

[Enrico Weigelt, metux IT consult]

Hi folks,


the legacy apu LEDs driver has been superseded by the more complete
pcengines-apu2 platform driver, for APU >= 2. It only supports
the three front LEDs, but lacks all the other GPIOs (eg. button
or simsw), and conflicts with the pcengines-apu2 driver.

Old APUv1 has a very different chipset.

Therefore I propose dropping the apu>=2 support from the legacy
driver, reducing it to only the old (obsolete) APUv1 boards.


--mtx