Currently the 'interrupts' and 'interrupt-names' properties are defined
being too generic to really describe any actual IRQ interface. Moreover
the DW PCIe End-point devices are left with no IRQ signals. All of that
can be fixed by adding the IRQ-related properties to the common DW PCIe
DT-schemas in accordance with the hardware reference manual. The DW PCIe
common DT-schema will contain the generic properties definitions with just
a number of entries per property, while the DW PCIe RP/EP-specific schemas
will have the particular number of items and the generic resource names
listed.

Note since there are DW PCI-based vendor-specific DT-bindings with the
custom names assigned to the same IRQ resources we have no much choice but
to add them to the generic DT-schemas in order to have the schemas being
applicable for such devices. These names are marked as vendor-specific and
should be avoided being used in new bindings in favor of the generic
names.

Link: https://lore.kernel.org/r/20221113191301.5526-10-Sergey.Semin@baikalelectronics.ruSigned-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>