dm: fix mis-word in SPL_DM description

Replace logically correct word in the description.

Fixes: 91a91ff804d ("dm: Add Kconfig options for driver model SPL support")
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@foundries.io>
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed