mfd: silergy,sy7636a: Add config option MFD_SY7636A

Add a specific MFD_SY7636A config option.

As part of this change we can use MFD_SY7636A as a dependency for all
SY7636a components and also remove the name from MFD_SIMPLE_MFD_I2C as
it no longer needs to be selectable.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20220525115554.430971-2-alistair@alistair23.me

drivers/hwmon/Kconfig

@@ -1745,6 +1745,7 @@ config SENSORS_SIS5595
 
 config SENSORS_SY7636A
 	tristate "Silergy SY7636A"
+	depends on MFD_SY7636A
 	help
 	  If you say yes here you get support for the thermistor readout of
 	  the Silergy SY7636A PMIC.

drivers/mfd/Kconfig

@@ -1133,6 +1133,16 @@ config MFD_SPMI_PMIC
 	  Say M here if you want to include support for the SPMI PMIC
 	  series as a module.  The module will be called "qcom-spmi-pmic".
 
+config MFD_SY7636A
+	tristate "Silergy SY7636A voltage regulator"
+	depends on I2C
+	select MFD_SIMPLE_MFD_I2C
+	help
+	  Enable support for Silergy SY7636A voltage regulator.
+
+	  To enable support for building sub-devices as modules,
+	  choose M here.
+
 config MFD_RDC321X
 	tristate "RDC R-321x southbridge"
 	select MFD_CORE
@@ -1240,7 +1250,7 @@ config MFD_SI476X_CORE
 	  module will be called si476x-core.
 
 config MFD_SIMPLE_MFD_I2C
-	tristate "Simple Multi-Functional Device support (I2C)"
+	tristate
 	depends on I2C
 	select MFD_CORE
 	select REGMAP_I2C

drivers/regulator/Kconfig

@@ -1264,6 +1264,7 @@ config REGULATOR_STW481X_VMMC
 
 config REGULATOR_SY7636A
 	tristate "Silergy SY7636A voltage regulator"
+	depends on MFD_SY7636A
 	help
 	  This driver supports Silergy SY3686A voltage regulator.