rtc: bq32000: add trickle charger device tree binding

rtc: bq32000: add trickle charger device tree binding

BQ32000 have "trickle chargers".  Introduce a device tree binding for
specifying the trickle charger configuration for that.

Signed-off-by: Pavel Machek <[email protected]>
Reviewed-by: Jason Cooper <[email protected]>
Cc: Matti Vaittinen <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Ian Campbell <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Guenter Roeck <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>