rockchip: rk3588-toybrick-x0: Migrate to OF_UPSTREAM

The device tree for Rockchip Toybrick TB-RK3588X has been merged into
dts/upstream with devicetree-rebasing v6.10-dts, migrate board to
OF_UPSTREAM.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/configs/toybrick-rk3588_defconfig b/configs/toybrick-rk3588_defconfig
index 5a19035..12a076a 100644
--- a/configs/toybrick-rk3588_defconfig
+++ b/configs/toybrick-rk3588_defconfig
@@ -2,7 +2,7 @@
 CONFIG_SKIP_LOWLEVEL_INIT=y
 CONFIG_COUNTER_FREQUENCY=24000000
 CONFIG_ARCH_ROCKCHIP=y
-CONFIG_DEFAULT_DEVICE_TREE="rk3588-toybrick-x0"
+CONFIG_DEFAULT_DEVICE_TREE="rockchip/rk3588-toybrick-x0"
 CONFIG_ROCKCHIP_RK3588=y
 CONFIG_SPL_SERIAL=y
 CONFIG_TARGET_TOYBRICK_RK3588=y
@@ -31,7 +31,6 @@
 # CONFIG_SPL_DOS_PARTITION is not set
 CONFIG_SPL_OF_CONTROL=y
 CONFIG_OF_LIVE=y
-# CONFIG_OF_UPSTREAM is not set
 CONFIG_OF_SPL_REMOVE_PROPS="clock-names interrupt-parent assigned-clocks assigned-clock-rates assigned-clock-parents"
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_SPL_DM_SEQ_ALIAS=y