uboot-rockchip: add ArmSoM Sige7 support

package/boot/uboot-rockchip/Makefile

@@ -282,6 +282,22 @@ define U-Boot/station-p2-rk3568
     firefly_station-p2
 endef
 
+# RK3588 boards
+
+define U-Boot/Default/rk3588
+  BUILD_SUBTARGET:=armv8
+  DEPENDS:=+PACKAGE_u-boot-$(1):rkbin-rk3588
+  ATF:=rk3588_bl31_v1.45.elf
+  TPL:=rk3588_ddr_lp4_2112MHz_lp5_2400MHz_v1.16.bin
+endef
+
+define U-Boot/sige7-rk3588
+  $(U-Boot/Default/rk3588)
+  NAME:=Sige7
+  BUILD_DEVICES:= \
+    armsom_sige7
+endef
+
 UBOOT_TARGETS := \
   panther-x2-rk3566 \
   rock-3c-rk3566 \
@@ -312,7 +328,8 @@ UBOOT_TARGETS := \
   nanopi-r2c-rk3328 \
   nanopi-r2s-rk3328 \
   orangepi-r1-plus-rk3328 \
-  orangepi-r1-plus-lts-rk3328
+  orangepi-r1-plus-lts-rk3328 \
+  sige7-rk3588
 
 UBOOT_CONFIGURE_VARS += USE_PRIVATE_LIBGCC=yes
 

package/boot/uboot-rockchip/patches/900-arm-add-dts-files.patch

@@ -8,3 +8,11 @@
  	rk3568-mrkaio-m68s.dtb \
  	rk3568-nanopi-r5s.dtb \
  	rk3568-photonicat.dtb \
+@@ -191,6 +191,7 @@
+ 	rk3568-rsb4810.dtb
+
+ dtb-$(CONFIG_ROCKCHIP_RK3588) += \
++	rk3588-armsom-sige7.dtb \
+ 	rk3588-edgeble-neu6a-io.dtb \
+ 	rk3588-evb1-v10.dtb \
+ 	rk3588-rock-5b.dtb

package/boot/uboot-rockchip/src/arch/arm/dts/rk3588-armsom-sige7-u-boot.dtsi

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "rk3588-u-boot.dtsi"
+
+/ {
+	chosen {
+		u-boot,spl-boot-order = "same-as-spl", &sdhci, &sdmmc;
+	};
+};
+
+&sdhci {
+	cap-mmc-highspeed;
+	mmc-ddr-1_8v;
+	mmc-hs200-1_8v;
+};