arm: dts: iot2050: Use the auto generator nodes for fdt

Refactor according to the entry `fit: Entry containing a FIT` of
document tools/binman/README.entries.

As the generator uses the device tree name for the config description,
board_fit_config_name_match requires a small adjustment as well.

Signed-off-by: Su Baocheng <baocheng.su@siemens.com>
[Jan: re-add now required CONFIG_OF_LIST, update config matching]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/siemens/iot2050/board.c b/board/siemens/iot2050/board.c
index dbf8930..57d7009 100644
--- a/board/siemens/iot2050/board.c
+++ b/board/siemens/iot2050/board.c
@@ -154,6 +154,9 @@
 	struct iot2050_info *info = IOT2050_INFO_DATA;
 	char upper_name[32];
 
+	/* skip the prefix "k3-am65x8-" */
+	name += 10;
+
 	if (info->magic != IOT2050_INFO_MAGIC ||
 	    strlen(name) >= sizeof(upper_name))
 		return -1;