dm: timer: Correct timer init ordering after relocation

Commit 1057e6cf broke use of the timer with driver model. If the timer is used
before relocation, then it becomes broken after relocation. This prevents
some x86 boards from booting. Fix it.

Fixes: 1057e6cf (timer: Set up the real timer after driver model is available)

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