Revert "clocksource/drivers/timer-of: Remove percpu irq related code"

This reverts commit 0af6b80d which is
commit 471ef0b5 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ifb7997f5d2493201b64b87a39aad659525299192
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>