arm64: dts: qcom: pms405: add unit name adc nodes

The adc nodes have reg property but were missing the unit name, so add
that to fix these warnings:

arch/arm64/boot/dts/qcom/pms405.dtsi:91.12-94.6: Warning (unit_address_vs_reg): /soc@0/spmi@200f000/pms405@0/adc@3100/ref_gnd: node has a reg or ranges property, but no unit name
arch/arm64/boot/dts/qcom/pms405.dtsi:96.14-99.6: Warning (unit_address_vs_reg): /soc@0/spmi@200f000/pms405@0/adc@3100/vref_1p25: node has a reg or ranges property, but no unit name
arch/arm64/boot/dts/qcom/pms405.dtsi:101.19-104.6: Warning (unit_address_vs_reg): /soc@0/spmi@200f000/pms405@0/adc@3100/vph_pwr: node has a reg or ranges property, but no unit name
arch/arm64/boot/dts/qcom/pms405.dtsi:106.13-109.6: Warning (unit_address_vs_reg): /soc@0/spmi@200f000/pms405@0/adc@3100/die_temp: node has a reg or ranges property, but no unit name
arch/arm64/boot/dts/qcom/pms405.dtsi:111.27-116.6: Warning (unit_address_vs_reg): /soc@0/spmi@200f000/pms405@0/adc@3100/thermistor1: node has a reg or ranges property, but no unit name
arch/arm64/boot/dts/qcom/pms405.dtsi:118.27-123.6: Warning (unit_address_vs_reg): /soc@0/spmi@200f000/pms405@0/adc@3100/thermistor3: node has a reg or ranges property, but no unit name
arch/arm64/boot/dts/qcom/pms405.dtsi:125.22-130.6: Warning (unit_address_vs_reg): /soc@0/spmi@200f000/pms405@0/adc@3100/xo_temp: node has a reg or ranges property, but no unit name

Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>