ARM: dts: imx7d-flex-concentrator: fix pcf2127 reset

RTC pcf2127 device driver has changed default behaviour of the watchdog
feature in v5.11-rc1. Now you need to explicitly enable it with a
device tree property, "reset-source", when used in the board design.

Fixes: 71ac13457d9d ("rtc: pcf2127: only use watchdog when explicitly available")
Signed-off-by: Bruno Thomsen <[e-mail]>
Cc: Bruno Thomsen <[e-mail]>
Cc: Uwe Kleine-König <[e-mail]>
Cc: Rasmus Villemoes <[e-mail]>
Reviewed-by: Alexandre Belloni <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

arch/arm/boot/dts/imx7d-flex-concentrator.dts

···
 		compatible = "nxp,pcf2127";
 		reg = <0>;
 		spi-max-frequency = <2000000>;
+		reset-source;
 	};
 };