uboot-imx

dm: Correct pre_reloc_only parameter description in several APIs' comments

The pre_reloc_only parameter description currently only mentions
drivers with the DM_FLAG_PRE_RELOC flag, but does not mention the
special device tree properties. Correct them.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>