nitrogen6x: change maintainer

Troy Kisky will be maintaining the Nitrogen6x board going forward.

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Acked-by: Troy Kisky <troy.kisky@boundarydevices.com>
diff --git a/board/boundary/nitrogen6x/MAINTAINERS b/board/boundary/nitrogen6x/MAINTAINERS
index cb06c03..1602d65 100644
--- a/board/boundary/nitrogen6x/MAINTAINERS
+++ b/board/boundary/nitrogen6x/MAINTAINERS
@@ -1,5 +1,5 @@
 NITROGEN6X BOARD
-M:	Eric Nelson <eric.nelson@boundarydevices.com>
+M:	Troy Kisky <troy.kisky@boundarydevices.com>
 S:	Maintained
 F:	board/boundary/nitrogen6x/
 F:	include/configs/nitrogen6x.h