board: phytec: imx8mp: Add PHYTEC phyCORE-i.MX8MP support

Add initial support PHYTEC phyCORE-i.MX8MP SOM.

    Supported features:
     - 2GB LPDDR4 RAM
     - eMMC
     - external SD
     - debug UART2
     - watchdog

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index ebdda1a..c0b4d9d 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -786,6 +786,7 @@
 	imx8mm-beacon-kit.dtb \
 	imx8mq-phanbell.dtb \
 	imx8mp-evk.dtb \
+	imx8mp-phyboard-pollux-rdk.dtb \
 	imx8mq-pico-pi.dtb
 
 dtb-$(CONFIG_ARCH_IMXRT) += imxrt1050-evk.dtb \