irqchip/gic-v2m: Mark a few functions __init

[ Upstream commit d51a15af37ce8cf59e73de51dcdce3c9f4944974 ]

They are all part of the init sequence.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221121140048.534395323@linutronix.de


Stable-dep-of: 3318dc299b07 ("irqchip/gic-v2m: Prevent use after free of gicv2m_get_fwnode()")
Signed-off-by: Sasha Levin <sashal@kernel.org>