Documentation: charger: max14577: Document exported sysfs entry

Document the 'fast charge timer' setting exported by max14577 driver
through sysfs entry.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Documentation/ABI/testing/sysfs-class-power

@@ -18,3 +18,17 @@ Description:
 		This file is writeable and can be used to set the assumed
 		battery 'full level'. As batteries age, this value has to be
 		amended over time.
+
+What:		/sys/class/power_supply/max14577-charger/device/fast_charge_timer
+Date:		July 2014
+KernelVersion:	3.18.0
+Contact:	Krzysztof Kozlowski <k.kozlowski@samsung.com>
+Description:
+		This entry shows and sets the maximum time the max14577
+		charger operates in fast-charge mode. When the timer expires
+		the device will terminate fast-charge mode (charging current
+		will drop to 0 A) and will trigger interrupt.
+
+		Valid values:
+		- 5, 6 or 7 (hours),
+		- 0: disabled.