board: rockchip: Add Pine64 PineTab2

The Pine64 PineTab2 is a tablet computer based on the Rockchip RK3566
SoC. The table features 4/8 GB LPDDR4 RAM and 64/128 GB eMMC storage.

Features tested on a Pine64 PineTab2 8GB v2.0:
- SD-card boot
- eMMC boot
- SPI Flash boot
- USB host

Device tree is imported from linux maintainer branch v6.9-armsoc/dts64,
commit 1b7e19448f8f ("arm64: dts: rockchip: Add devicetree for Pine64
PineTab2").

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3566-pinetab2-u-boot.dtsi b/arch/arm/dts/rk3566-pinetab2-u-boot.dtsi
new file mode 100644
index 0000000..4aa6ab1
--- /dev/null
+++ b/arch/arm/dts/rk3566-pinetab2-u-boot.dtsi
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include "rk356x-u-boot.dtsi"
+
+&fspi_dual_io_pins {
+	bootph-all;
+};
+
+&gpio0 {
+	bootph-all;
+};
+
+&i2c0 {
+	bootph-pre-ram;
+};
+
+&rk817 {
+	bootph-pre-ram;
+
+	regulators {
+		bootph-pre-ram;
+	};
+};
+
+&sdhci {
+	cap-mmc-highspeed;
+};
+
+&sdmmc_pwren_l {
+	bootph-all;
+};
+
+&sfc {
+	bootph-pre-ram;
+	u-boot,spl-sfc-no-dma;
+
+	flash@0 {
+		bootph-pre-ram;
+	};
+};
+
+&vcc3v3_sd {
+	bootph-pre-ram;
+};