ARM: dts: qcom: msm8974-sony-*: fix multi-led node name

The name rgb-led is not allowed, multi-led is supposed to be used.

<snip>/arch/arm/boot/dts/qcom-msm8974-sony-xperia-rhine-amami.dtb: pm8941@1: pwm: 'rgb-led' does not match any of the regexes: '^led@[0-9a-f]$', 'pinctrl-[0-9]+'
        From schema: <snip>/Documentation/devicetree/bindings/mfd/qcom,spmi-pmic.yaml

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220925175631.103535-1-luca@z3ntu.xyz