imx: imx8qm_rom7720_a1: add missing DTS to the MAINTAINERS

add the dts file to the MAINTAINERS entry

Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: uboot-imx <uboot-imx@nxp.com>
diff --git a/board/advantech/imx8qm_rom7720_a1/MAINTAINERS b/board/advantech/imx8qm_rom7720_a1/MAINTAINERS
index b142ee0..58a4d25 100644
--- a/board/advantech/imx8qm_rom7720_a1/MAINTAINERS
+++ b/board/advantech/imx8qm_rom7720_a1/MAINTAINERS
@@ -2,5 +2,6 @@
 M:	Oliver Graute <oliver.graute@kococonnector.com>
 S:	Maintained
 F:	board/advantech/imx8qm_rom7720_a1/
+F:	arch/arm/dts/imx8qm-rom7720-a1.dts
 F:	include/configs/imx8qm_rom7720.h
 F:	configs/imx8qm_rom7720_a1_4G_defconfig