i2c: pnx: Fix potential deadlock warning from del_timer_sync() call in isr

i2c: pnx: Fix potential deadlock warning from del_timer_sync() call in isr

When del_timer_sync() is called in an interrupt context it throws a warning
because of potential deadlock. The timer is used only to exit from
wait_for_completion() after a timeout so replacing the call with
wait_for_completion_timeout() allows to remove the problematic timer and
its related functions altogether.

Fixes: 41561f28e76a ("i2c: New Philips PNX bus driver")
Signed-off-by: Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>