board: rockchip: Add Xunlong Orange Pi 3B

The Xunlong Orange Pi 3B is a single-board computer based on the
Rockchip RK3566 SoC.

The two hw revisions use different io-voltage for Ethernet PHY and can
be identified using GPIO4_C4:
- v1.1.1: x (internal pull-down)
- v2.1:   PHY_RESET (external pull-up)

Implement rk_board_late_init() to set correct fdtfile env var and
board_fit_config_name_match() to load correct FIT config based on what
board is detected at runtime so a single board target can be used for
both hw revisions.

Minimal DTs that includ DT from dts/upstream is added to support booting
from both hw revision and only set Ethernet PHY io-voltage when the hw
revision is detected at runtime. A side-affect of this is that defconfig
show OF_UPSTREAM=n, however dts/upstream DTs is used for this board.

Features tested on Orange Pi 3B 4GB (v1.1.1 and v2.1):
- SD-card boot
- eMMC boot
- SPI Flash boot
- Ethernet
- PCIe/NVMe
- USB host

Signed-off-by: Ricardo Pardini <ricardo@pardini.net>
Co-developed-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/board/xunlong/orangepi-3b-rk3566/Makefile b/board/xunlong/orangepi-3b-rk3566/Makefile
new file mode 100644
index 0000000..9ce2554
--- /dev/null
+++ b/board/xunlong/orangepi-3b-rk3566/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-y += orangepi-3b-rk3566.o