arm64: dts: broadcom: Add reference to Compute Module IO Board V3

This adds a reference to the dts of the Compute Module IO Board V3 in arm,
so we don't need to maintain the content in arm64.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>

arch/arm64/boot/dts/broadcom/Makefile

 # SPDX-License-Identifier: GPL-2.0
 dtb-$(CONFIG_ARCH_BCM2835) += bcm2837-rpi-3-b.dtb \
-			      bcm2837-rpi-3-b-plus.dtb
+			      bcm2837-rpi-3-b-plus.dtb \
+			      bcm2837-rpi-cm3-io3.dts
 
 subdir-y	+= northstar2
 subdir-y	+= stingray

arch/arm64/boot/dts/broadcom/bcm2837-rpi-cm3-io3.dts

+// SPDX-License-Identifier: GPL-2.0
+#include "arm/bcm2837-rpi-cm3-io3.dts"