* Dallas DS1390		SPI Serial Real-Time Clock

Required properties:
- compatible: Should contain "dallas,ds1390".
- reg: SPI address for chip

Optional properties:
- trickle-resistor-ohms : Selected resistor for trickle charger
	Values usable for ds1390 are 250, 2000, 4000
	Should be given if trickle charger should be enabled
- trickle-diode-disable : Do not use internal trickle charger diode
	Should be given if internal trickle charger diode should be disabled
Example:
	ds1390: rtc@68 {
		compatible = "dallas,ds1390";
		trickle-resistor-ohms = <250>;
		reg = <0>;
	};
