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

arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi

@@ -308,7 +308,10 @@ keyboard_backlight: keyboard-backlight {
 };
 
 /*
- * BOARD-LOCAL NAMES FOR REGULATORS THAT CONNECT TO QCARD
+ * ADJUSTMENTS TO QCARD REGULATORS
+ *
+ * Mostly this is just board-local names for regulators that come from
+ * Qcard, but this also has some minor regulator overrides.
  *
  * Names are only listed here if regulators go somewhere other than a
  * testpoint.
@@ -352,6 +355,16 @@ keyboard_backlight: keyboard-backlight {
 ts_avdd:      &pp3300_left_in_mlb {};
 vreg_edp_3p3: &pp3300_left_in_mlb {};
 
+/* Regulator overrides from Qcard */
+
+/*
+ * Herobrine boards only use l2c to power an external audio codec (like
+ * alc5682) and we want that to be at 1.8V, not at some slightly lower voltage.
+ */
+&vreg_l2c_1p8 {
+	regulator-min-microvolt = <1800000>;
+};
+
 /* ADDITIONS TO NODES DEFINED IN PARENT DEVICE TREE FILES */
 
 ap_sar_sensor_i2c: &i2c1 {