ARM: dts: imx6ul-kontron: Change WDOG_ANY signal from push-pull to open-drain

The WDOG_ANY signal is connected to the RESET_IN signal of the SoM
and baseboard. It is currently configured as push-pull, which means
that if some external device like a programmer wants to assert the
RESET_IN signal by pulling it to ground, it drives against the high
level WDOG_ANY output of the SoC.

To fix this we set the WDOG_ANY signal to open-drain configuration.
That way we make sure that the RESET_IN can be asserted by the
watchdog as well as by external devices.

Fixes: 1ea4b76c ("ARM: dts: imx6ul-kontron-n6310: Add Kontron i.MX6UL N6310 SoM and boards")
Cc: stable@vger.kernel.org
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>