The label on the l15 regulator node does not follow the style of the
rest of the regulator nodes.  Luckily, no one has used the label yet,
so lets fix it.

Fixes: 2c6d2d3a ("arm64: dts: qcom: Add Lenovo Miix 630")
Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Link: https://lore.kernel.org/r/20200528145135.44269-1-jeffrey.l.hugo@gmail.comSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>