arm64: dts: qcom: apq8016-sbc: Remove wrong regulator supply

As specified in the smd-rpm-regulator binding and confirmed by the
pm8616 device specification, there is no vdd_l5. l5 vdd comes from
vdd_l4_l5_l6. Fix that (though it does not cause any issue since
the supply is not requested).

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1583516368-29593-1-git-send-email-loic.poulain@linaro.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>