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 55a68c23e0a675b2b8ac2656fd6edbf98b78e4c6.

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>