Apexq: fix charger current reporting error bq24157.

Somebody at samsung didn't read the documentation.
When the current limit was set for 950, it read out
as 900. When the current limit was set for 500, it
read out as 100. This charger does not permit any
fast charge current limit to be set for under 550 mA.

Change-Id: I98d5a302d17bfcb5a942f5a66752f34dcfff40fc