irqchip/qcom-pdc: Kill non-wakeup irqdomain

A careful look at the way the PDC driver works shows that:

- all interrupts are in the same space
- all interrupts are treated the same

And yet the driver creates two domains based on whether
the interrupt gets mapped directly or from the pinctrl code,
which is obviously a waste of resources.

Kill the non-wakeup domain and unify all the interrupt handling.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220224101226.88373-3-maz@kernel.org