x86: link: Correct a failure in DRAM init

With the change to set up pinctrl after relocation, link fails to boot. Add
a special case in the link code to handle this.

Fixes: d8906c1f (x86: Probe pinctrl driver in cpu_init_r())

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