irqchip/irq-imx-gpcv2: Forward irq type to parent

[ Upstream commit 9a446ef08f3bfc0c3deb9c6be840af2528ef8cf8 ]

The GPCv2 is a stacked IRQ controller below the ARM GIC. It doesn't
care about the IRQ type itself, but needs to forward the type to the
parent IRQ controller, so this one can be configured correctly.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>