arm64: dts: qcom: sc7280-herobrine: Audio codec wants 1.8V, not 1.62V

The L2C rail on herobrine boards is intended to go to the audio
codec. Let's override the 1.62V specified in the qcard.dtsi file to be
1.8V.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220411141332.v2.1.I9f06fec63b978699fe62591fec9e5ac31bb3a69d@changeid