irqdomain/debugfs: Use PAs to generate fwnode names

Booting a large arm64 server (HiSi D05) leads to the following
shouting at boot time:

[   20.722132] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[   20.730851] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[   20.739560] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[   20.748267] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[   20.756975] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[   20.765683] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[   20.774391] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!

and many more... Evidently, we expect something a bit more informative
than ____ptrval____, and certainly we want all of our domains, not just
the first one.

For that, turn the %p used to generate the fwnode name into something
that won't be repainted (%pa). Given that we've now fixed all users to
pass a pointer to a PA, it will actually do the right thing.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>