rockchip: rk3588: Add default u-boot,spl-boot-order prop

Add a default u-boot,spl-boot-order prop to rk3588s-u-boot.dtsi and
remove the prop from board u-boot.dtsi files using the default value.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Eugen Hristev <eugen.hristev@collabora.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3588s-u-boot.dtsi b/arch/arm/dts/rk3588s-u-boot.dtsi
index d251a21..945b2d6 100644
--- a/arch/arm/dts/rk3588s-u-boot.dtsi
+++ b/arch/arm/dts/rk3588s-u-boot.dtsi
@@ -10,6 +10,10 @@
 		spi5 = &sfc;
 	};
 
+	chosen {
+		u-boot,spl-boot-order = "same-as-spl", &sdmmc, &sdhci;
+	};
+
 	dmc {
 		compatible = "rockchip,rk3588-dmc";
 		bootph-all;