MAINTAINERS: Add Applied Micro (APM) X-Gene Device Tree maintainer
MAINTAINERS: Add Applied Micro (APM) X-Gene Device Tree maintainer

This patch adds information of maintainers for Applied Micro (APM)
X-Gene device tree.

Signed-off-by: Duc Dang <02e69028202e3ab4ba908f4d29572c8c5e579377@apm.com>

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