For the CRC PMIC we end up with multiple IRQ domains with the same fwnode.
One for the irqchip which demultiplexes the actual PMIC interrupt into
interrupts for the various cells (known as the level 1 interrupts);

And 2 more for the irqchips which are part of the crystal_cove_gpio
and crystal_cove_charger cells.

This leads to the following error being printed when
CONFIG_GENERIC_IRQ_DEBUGFS is enabled:
 debugfs: File '\_SB.I2C7.PMIC' in directory 'domains' already present!

Set the bus token of the main IRQ domain to DOMAIN_BUS_NEXUS to avoid
this error, this also allows irq_find_matching_fwspec() to find the
right domain if necessary.

Note all 3 domain registering drivers need to set the IRQ domain bus token.
This is necessary because the IRQ domain code defaults to creating
the debugfs dir with just the fwnode name and then renames it when
the bus token is set. So each one starts with the same default name and
all 3 must be given a different name to avoid problems when one of the
other drivers loads and starts with the same default name.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211225115509.94891-4-hdegoede@redhat.com