dt-bindings: iio: adc: mt6359: Add MT6373 PMIC AuxADC

Add a compatible and channel bindings for MediaTek's MT6373 PMIC,
featuring an Auxiliary ADC IP with 15 ADC channels for external
(SoC) temperatures and external voltage inputs.

Acked-by: Rob Herring (Arm) <[e-mail]>
Reviewed-by: Nícolas F. R. A. Prado <[e-mail]>
Signed-off-by: AngeloGioacchino Del Regno <[e-mail]>
Reviewed-by: Nuno Sá <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

Documentation/devicetree/bindings/iio/adc/mediatek,mt6359-auxadc.yaml

···
       - mediatek,mt6358-auxadc
       - mediatek,mt6359-auxadc
       - mediatek,mt6363-auxadc
+      - mediatek,mt6373-auxadc
 
   "#io-channel-cells":
     const: 1

include/dt-bindings/iio/adc/mediatek,mt6373-auxadc.h

···
+/* SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause */
+
+#ifndef _DT_BINDINGS_MEDIATEK_MT6373_AUXADC_H
+#define _DT_BINDINGS_MEDIATEK_MT6373_AUXADC_H
+
+/* ADC Channel Index */
+#define MT6373_AUXADC_CHIP_TEMP		0
+#define MT6373_AUXADC_VCORE_TEMP	1
+#define MT6373_AUXADC_VPROC_TEMP	2
+#define MT6373_AUXADC_VGPU_TEMP		3
+#define MT6373_AUXADC_VIN1		4
+#define MT6373_AUXADC_VIN2		5
+#define MT6373_AUXADC_VIN3		6
+#define MT6373_AUXADC_VIN4		7
+#define MT6373_AUXADC_VIN5		8
+#define MT6373_AUXADC_VIN6		9
+#define MT6373_AUXADC_VIN7		10
+
+#endif