arm: octeontx: Add an empty devicetree file

Add an empty file to prevent build errors when building with
CONFIG_OF_SEPARATE enabled.

Unfortunately there are no build instructions in the U-Boot tree to enable
a real file to be created.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/arm/dts/Makefile

@@ -1142,6 +1142,9 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += \
 
 dtb-$(CONFIG_XEN) += xenguest-arm64.dtb
 
+dtb-$(CONFIG_ARCH_OCTEONTX) += octeontx.dtb
+dtb-$(CONFIG_ARCH_OCTEONTX2) += octeontx.dtb
+
 dtb-$(CONFIG_TARGET_GE_BX50V3) += \
 	imx6q-bx50v3.dtb \
 	imx6q-b850v3.dtb \

arch/arm/dts/octeontx.dts

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Dummy devicetre file for octeontx2 boards
+ *
+ * This is required to make the board build with CONFIG OF_SEPARATE
+ * I could not find any in-tree documentation at all so this is a dummy file.
+ *
+ * Copyright 2021 Google LLC
+ */
+
+/dts-v1/;
+
+/ {
+};

configs/octeontx2_95xx_defconfig

@@ -12,6 +12,7 @@ CONFIG_ENV_OFFSET=0xF00000
 CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_TARGET_OCTEONTX2_95XX=y
 CONFIG_DM_GPIO=y
+CONFIG_DEFAULT_DEVICE_TREE="octeontx"
 CONFIG_DEBUG_UART_BASE=0x87e028000000
 CONFIG_DEBUG_UART_CLOCK=24000000
 CONFIG_DEBUG_UART=y

configs/octeontx2_96xx_defconfig

@@ -10,6 +10,7 @@ CONFIG_ENV_OFFSET=0xF00000
 CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_TARGET_OCTEONTX2_96XX=y
 CONFIG_DM_GPIO=y
+CONFIG_DEFAULT_DEVICE_TREE="octeontx"
 CONFIG_DEBUG_UART_BASE=0x87e028000000
 CONFIG_DEBUG_UART_CLOCK=24000000
 CONFIG_DEBUG_UART=y

configs/octeontx_81xx_defconfig

@@ -12,6 +12,7 @@ CONFIG_ENV_OFFSET=0xF00000
 CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_TARGET_OCTEONTX_81XX=y
 CONFIG_DM_GPIO=y
+CONFIG_DEFAULT_DEVICE_TREE="octeontx"
 CONFIG_DEBUG_UART_BASE=0x87e028000000
 CONFIG_DEBUG_UART_CLOCK=24000000
 CONFIG_DEBUG_UART=y

configs/octeontx_83xx_defconfig

@@ -10,6 +10,7 @@ CONFIG_ENV_OFFSET=0xF00000
 CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_TARGET_OCTEONTX_83XX=y
 CONFIG_DM_GPIO=y
+CONFIG_DEFAULT_DEVICE_TREE="octeontx"
 CONFIG_DEBUG_UART_BASE=0x87e028000000
 CONFIG_DEBUG_UART_CLOCK=24000000
 CONFIG_DEBUG_UART=y