Based on the datasheet found here:
http://www.ti.com/lit/ds/symlink/bq24257.pdfSigned-off-by: NLaurentiu Palcu <laurentiu.palcu@intel.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>