irqchip: Allow extra fields to be passed to IRQCHIP_PLATFORM_DRIVER_END

IRQCHIP_PLATFORM_DRIVER_* doesn't allow some fields (such as .pm)
to be set in the platform_driver structure.

Make IRQCHIP_PLATFORM_DRIVER_END variadic so that .pm or another
field can be set if needed.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
[maz: revamped commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220922161246.20586-3-Frank.Li@nxp.com