power_supply: Add support for TI BQ25890 charger chip

More details about the chip can be found here:
http://www.ti.com/product/bq25890



Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>