dt-bindings: pci: layerscape-pci: define AER/PME interrupts

Different platforms using this controller are using different numbers of
interrupt lines and the routing of events to these interrupt lines are
different too.  So instead of trying to define names for these interrupt
lines, we define the more specific AER/PME events that are routed to
these interrupt lines.

For platforms which only has a single interrupt line for miscellaneous
controller events, we can keep using the original "intr" name for
backward compatibility.

Also change the example from ls1021a to ls1088a for better representation.

Link: https://lore.kernel.org/r/20220311234938.8706-5-leoyang.li@nxp.com


Signed-off-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>