power: bq24257: Add basic support for bq24250/bq24251

This patch adds basic support for bq24250 and bq24251 which are very
similar to the bq24257 the driver was originally written for. Basic
support means the ability to select a device through Kconfig, DT and
ACPI, an instance variable allowing to check which chip is active, and
the reporting back of the selected device through the model_name power
supply sysfs property.

This patch by itself is not sufficient to actually use those two added
devices in a real-world setting due to some feature differences which
are addressed by other patches in this series.

Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/Kconfig

@@ -409,12 +409,13 @@ config CHARGER_BQ24190
 	  Say Y to enable support for the TI BQ24190 battery charger.
 
 config CHARGER_BQ24257
-	tristate "TI BQ24257 battery charger driver"
+	tristate "TI BQ24250/24251/24257 battery charger driver"
 	depends on I2C
 	depends on GPIOLIB || COMPILE_TEST
 	depends on REGMAP_I2C
 	help
-	  Say Y to enable support for the TI BQ24257 battery charger.
+	  Say Y to enable support for the TI BQ24250, BQ24251, and BQ24257 battery
+	  chargers.
 
 config CHARGER_BQ24735
 	tristate "TI BQ24735 battery charger support"