rtc: rtc-mv: Add support for clk to avoid lockups

The Marvell RTC on Kirkwood makes use of the runit clock. Ensure the
driver clk_prepare_enable() this clock, otherwise there is a danger
the SoC will lockup when accessing RTC registers with the clock
disabled.

Reported-by: Simon Baatz <gmbnomis@gmail.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Simon Baatz <gmbnomis@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi
index cf8e892..fada7e6 100644
--- a/arch/arm/boot/dts/kirkwood.dtsi
+++ b/arch/arm/boot/dts/kirkwood.dtsi
@@ -75,6 +75,7 @@
 			compatible = "marvell,kirkwood-rtc", "marvell,orion-rtc";
 			reg = <0x10300 0x20>;
 			interrupts = <53>;
+			clocks = <&gate_clk 7>;
 		};
 
 		spi@10600 {