rockchip: rk3308: Migrate to OF_UPSTREAM

All RK3308 boards has now been synced to Linux kernel v6.8 DTs and can
migrate to use OF_UPSTREAM.

Migrate all RK3308 boards to use OF_UPSTREAM.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/configs/rock-pi-s-rk3308_defconfig b/configs/rock-pi-s-rk3308_defconfig
index 37a124e..c15ba3d 100644
--- a/configs/rock-pi-s-rk3308_defconfig
+++ b/configs/rock-pi-s-rk3308_defconfig
@@ -2,7 +2,7 @@
 CONFIG_SKIP_LOWLEVEL_INIT=y
 CONFIG_COUNTER_FREQUENCY=24000000
 CONFIG_ARCH_ROCKCHIP=y
-CONFIG_DEFAULT_DEVICE_TREE="rk3308-rock-pi-s"
+CONFIG_DEFAULT_DEVICE_TREE="rockchip/rk3308-rock-pi-s"
 CONFIG_OF_LIBFDT_OVERLAY=y
 CONFIG_DM_RESET=y
 CONFIG_ROCKCHIP_RK3308=y