ARC: IRQ: drop excessive PM_DEVICE hooks

All ARC CPUs (supported by Zephyr) don't lose core interrupt
controller configuration after switching to sleep mode / modes,
so we don't need to save & restore it's configuration with PM.

This PM code most likely was added for Arduino 101 (Genuino 101)
board which isn't supported by Zephyr anymore - so we can drop
it.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Evgeniy Paltsev <PaltsevEvgeniy@gmail.com>