arm64: dts: Add poweroff button device node for APM X-Gene platform
arm64: dts: Add poweroff button device node for APM X-Gene platform

This patch adds poweroff button device node to support poweroff feature
on APM X-Gene Mustang platform.

Signed-off-by: Y Vo <2eaf8cce1cef781007f71a326a8f1c24033065ba@apm.com>
Signed-off-by: Kevin Hilman <f9849b02abe18c1ece6bd40346458ed53f49d31b@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs