rak7268v2: Disable dying-gasp key / fix failsafe triggered on boot.

In some cases, the gateway boots unintended into failsafe mode, which
starts with the following message:

- failsafe button BTN_7 was pressed -

Removing this mapping from the device-tree should avoid this issue.

Author: brocaar

conf/rak_rak7268v2/patches/rak636_device.patch

@@ -2,7 +2,7 @@ Index: openwrt/target/linux/ramips/dts/mt7628an_rakwireless_rak636.dts
 ===================================================================
 --- /dev/null
 +++ openwrt/target/linux/ramips/dts/mt7628an_rakwireless_rak636.dts
-@@ -0,0 +1,175 @@
+@@ -0,0 +1,178 @@
 +// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
 +
 +#include "mt7628an.dtsi"
@@ -48,11 +48,14 @@ Index: openwrt/target/linux/ramips/dts/mt7628an_rakwireless_rak636.dts
 +			linux,code = <0x198>;
 +		};
 +
-+		dying-gasp {
-+			label = "dying-gasp";
-+			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
-+			linux,code = <BTN_7>;
-+		};
++		// Disabled, as this might trigger the gateway to boot into failsafe
++		// mode in some cases, in which case it will no longer be remotely
++		// accessible.
++		// dying-gasp {
++		//	label = "dying-gasp";
++		//	gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
++		//	linux,code = <BTN_7>;
++		// };
 +	};
 +};
 +