regulator: add support for MP8869 regulator

The MP8869 from Monolithic Power Systems is a single output DC/DC
converter. The voltage can be controlled via I2C.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200316223020.1a6d92ae@xhacker
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 64a39f34..f4b72cb 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -635,6 +635,13 @@
 	  Say M here if you want to include support for the regulator as a
 	  module. The module will be named "mp8859".
 
+config REGULATOR_MP886X
+	tristate "MPS MP8869 regulator driver"
+	depends on I2C && (OF || COMPILE_TEST)
+	select REGMAP_I2C
+	help
+	  This driver supports the MP8869 voltage regulator.
+
 config REGULATOR_MPQ7920
 	tristate "Monolithic MPQ7920 PMIC"
 	depends on I2C && OF