Current dts files with 'gpio-led' nodes were manually verified.
In order to automate this process leds-gpio.txt
has been converted to yaml. With this conversion a check
for pattern properties was added. A test with the command
below gives a screen full of warnings like:

arch/arm64/boot/dts/rockchip/rk3368-r88.dt.yaml: gpio-leds:
'work' does not match any of the regexes:
'(^led-[0-9a-f]$|led)', 'pinctrl-[0-9]+'

Fix these errors with help of the following rules:

1: Add nodename in the preferred form.

2: Always add a label that ends with '_led' to prevent conflicts
   with other labels such as 'power' and 'mmc'

3: If leds need pinctrl add a label that ends with '_led_pin'
   also to prevent conflicts with other labels.

patternProperties:
  # The first form is preferred, but fall back to just 'led'
  # anywhere in the node name to at least catch some child nodes.
  "(^led-[0-9a-f]$|led)":

make ARCH=arm64 dtbs_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/leds/
leds-gpio.yaml
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/20200428144933.10953-2-jbx6244@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>