dm: core: remove the duplicated function dm_ofnode_pre_reloc

dm: core: remove the duplicated function dm_ofnode_pre_reloc

The content dm_ofnode_pre_reloc() is identical with ofnode_pre_reloc()
defined in drivers/core/ofnode.c and used only three times:
- drivers/core/lists.c:lists_bind_fdt()
- drivers/clk/at91/pmc.c::at91_clk_sub_device_bind
- drivers/clk/altera/clk-arria10.c::socfpga_a10_clk_bind

So this function dm_ofnode_pre_reloc can be removed and replaced
by these function calls by ofnode_pre_reloc().

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Acked-by: Simon Glass <sjg@chromium.org>