arm64: dts: qcom: align LED node names with dtschema

The node names should be generic and DT schema expects certain pattern:

  qcom/msm8998-oneplus-cheeseburger.dtb: leds: 'button-backlight' does not match any of the regexes: '(^led-[0-9a-f]$|led)', 'pinctrl-[0-9]+'
  qcom/sc7180-trogdor-coachz-r1.dtb: pwmleds: 'keyboard-backlight' does not match any of the regexes: '^led(-[0-9a-f]+)?$', 'pinctrl-[0-9]+'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221125144209.477328-1-krzysztof.kozlowski@linaro.org