soc/tegra: pmc: Fix crashes for hierarchical interrupts

soc/tegra: pmc: Fix crashes for hierarchical interrupts

commit c9e753767a9c75d2044fb7343950a6a992d34a16 upstream.

Interrupts that don't have an associated wake event or GPIO wake events
end up with an associate IRQ chip that is NULL and which causes IRQ code
to crash. This is because we don't implicitly set the parent IRQ chip by
allocating the interrupt at the parent. However, there really isn't a
corresponding interrupt at the parent, so we need to work around this by
setting the special no_irq_chip as the IRQ chip for these interrupts.

Fixes: 19906e6b1667 ("soc/tegra: pmc: Add wake event support")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>