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/arch/arm/mach-rockchip/rk3568/Kconfig b/arch/arm/mach-rockchip/rk3568/Kconfig
index 0f32f24..899cf90 100644
--- a/arch/arm/mach-rockchip/rk3568/Kconfig
+++ b/arch/arm/mach-rockchip/rk3568/Kconfig
@@ -37,6 +37,11 @@
 	help
 	  Radxa ZERO 3W/3E single board computers with a RK3566 SoC.
 
+config TARGET_ORANGEPI_3B_RK3566
+	bool "Xunlong Orange Pi 3B"
+	help
+	  Xunlong Orange Pi 3B single board computer with a RK3566 SoC.
+
 endchoice
 
 config ROCKCHIP_BOOT_MODE_REG
@@ -60,5 +65,6 @@
 source "board/pine64/quartz64_rk3566/Kconfig"
 source "board/powkiddy/x55/Kconfig"
 source "board/radxa/zero3-rk3566/Kconfig"
+source "board/xunlong/orangepi-3b-rk3566/Kconfig"
 
 endif