arm64: dts: qcom: pm8916: Remove wrong reg-names for rtc@6000

While removing the size from the "reg" properties in pm8916.dtsi,
commit bd6429e8 ("ARM64: dts: qcom: Remove size elements from
pmic reg properties") mistakenly also removed the second register
address for the rtc@6000 device. That one did not represent the size
of the register region but actually the address of the second "alarm"
register region of the rtc@6000 device.

Now there are "reg-names" for two "reg" elements, but there is actually
only one "reg" listed.

Since the DT schema for "qcom,pm8941-rtc" only expects one "reg"
element anyway, just drop the "reg-names" entirely to fix this.

Fixes: bd6429e8 ("ARM64: dts: qcom: Remove size elements from pmic reg properties")
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210928112945.25310-1-stephan@gerhold.net