vibrator, volume buttons and rgb led

Please test :)

Vibrator: fftest $INPUT on the correct input device

Volume buttons: evtest

LEDs: echo 1 > /sys/class/leds/$LED/brightness

For me, volume buttons and vibrator work fine (although the vibrator is a bit weak but it doesn't seem adjustable). The red and green leds work fine, but the blue one doesn't for me (although checking with a multimeter it seems like it should work). Also you can't activate two at the same time to get a mixed color (e.g. red & green = yellow).

The first two commits in this MR (Input: add a driver for GPIO controllable vibrators) and Input: sun4i-a10-lradc-keys - add support for A83T) are in mainline (v5.2) already - and dt-bindings: input: sun4i-lradc-keys: Add A64 compatible and arm64: dts: allwinner: a64: Add lradc node are queued for 5.3