drivers/rtc/rtc-palmas.c: add dt support

Add of_device_id table for Palma RTC to be enable the driver from DT file.

The driver can be registered from DT file as:
	palmas: tps65913@58 {
		:::::::::::
		palmas_rtc {
			compatible = "ti,palmas-rtc";
			interrupt-parent = <&palmas>;
			interrupts = <8 0>;
		};
	};

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>