iio: adc: Add driver for Marvell 88PM886 PMIC ADC

Marvell's 88PM886 PMIC has a so-called General Purpose ADC used for
monitoring various system voltages and temperatures. Add the relevant
register definitions to the MFD header and a driver for the ADC.

Acked-by: Karel Balej <balejk@matfyz.cz> # for the PMIC
Signed-off-by: Duje Mihanović <duje@dujemihanovic.xyz>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: LegoLivesMatter

MAINTAINERS

@@ -14714,6 +14714,11 @@ F:	drivers/regulator/88pm886-regulator.c
 F:	drivers/rtc/rtc-88pm886.c
 F:	include/linux/mfd/88pm886.h
 
+MARVELL 88PM886 PMIC GPADC DRIVER
+M:	Duje Mihanović <duje@dujemihanovic.xyz>
+S:	Maintained
+F:	drivers/iio/adc/88pm886-gpadc.c
+
 MARVELL ARMADA 3700 PHY DRIVERS
 M:	Miquel Raynal <miquel.raynal@bootlin.com>
 S:	Maintained