dt-bindings: PCI: ti,j721e-pci-*: Add missing interrupt properties

Both interrupts, and interrupt names weren't defined in both EP and host
yaml. Also define the only possible interrupt-name as link_state, and
maxItems of interrupts to one.

This patch resolves the following warning:

arch/arm64/boot/dts/ti/k3-j721s2-common-proc-board.dtb: pcie-ep@2910000: Unevaluated properties are not allowed ('interrupt-names', 'interrupts' were unexpected)
        From schema Documentation/devicetree/bindings/pci/ti,j721e-pci-ep.yaml

Link: https://lore.kernel.org/r/20221025081909.404107-3-mranostay@ti.com


Signed-off-by: Matt Ranostay <mranostay@ti.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>