uboot-phytec

dm: Fix typo in include-guard for dm-structs.h

The include-guard for dm-structs.h was misspelled as __DT_STTUCTS.
Change it.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>