Revert "dw_apb_timer_of.c: Remove parts that were picoxcell-specific"

Revert "dw_apb_timer_of.c: Remove parts that were picoxcell-specific"

This reverts commit c2ffba78db250b642b8741f8a912af874522a1ae.

In order to avoid a collision with dw_apb_timer changes in
the arm-soc tree, revert this change.

I'm leaving it to the arm-soc folks to sort out if they want
to keep the other side of the collision or if they're just going
to back it all out and try again during the next release cycle.

Reported-by: Dinh Nguyen <dinguyen@altera.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>