imx: imx8mp: Add support for Polyhex Debix Model A SBC

Add support for the Polyhex Debix Model A SBC board.
It is an industrial grade single board computer based on
NXP's i.MX 8M Plus.
Currently supported interfaces are:
- Serial console
- Micro SD
- eQOS and FEC Ethernet

imx8mp-debix-model-a.dts is taken from Linux 6.3.

Signed-off-by: Gilles Talis <gilles.talis@gmail.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index ea420db..b415613 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -1104,6 +1104,7 @@
 	imx8mp-dhcom-som-overlay-eth1xfast.dtbo \
 	imx8mp-dhcom-som-overlay-eth2xfast.dtbo \
 	imx8mp-dhcom-pdk-overlay-eth2xfast.dtbo \
+	imx8mp-debix-model-a.dtb \
 	imx8mp-dhcom-pdk2.dtb \
 	imx8mp-dhcom-pdk3.dtb \
 	imx8mp-dhcom-pdk3-overlay-rev100.dtbo \