dt-bindings: PCI: cadence: Add PCIe RC/EP DT schema for Cadence PCIe

Add PCIe Host (RC) and Endpoint (EP) device tree schema for Cadence
PCIe core library. Platforms using Cadence PCIe core can include the
schemas added here in the platform specific schemas.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/pci/cdns-pcie-host.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/pci/cdns-pcie-host.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Cadence PCIe Host
+
+maintainers:
+  - Tom Joseph <tjoseph@cadence.com>
+
+allOf:
+  - $ref: "/schemas/pci/pci-bus.yaml#"
+  - $ref: "cdns-pcie.yaml#"
+
+properties:
+  cdns,no-bar-match-nbits:
+    description:
+      Set into the no BAR match register to configure the number of least
+      significant bits kept during inbound (PCIe -> AXI) address translations
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 64
+    default: 32
+
+  msi-parent: true

Documentation/devicetree/bindings/pci/cdns-pcie.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/pci/cdns-pcie.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Cadence PCIe Core
+
+maintainers:
+  - Tom Joseph <tjoseph@cadence.com>
+
+properties:
+  cdns,max-outbound-regions:
+    description: maximum number of outbound regions
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 32
+    default: 32
+
+  phys:
+    description:
+      One per lane if more than one in the list. If only one PHY listed it must
+      manage all lanes.
+    minItems: 1
+    maxItems: 16
+
+  phy-names:
+    items:
+      - const: pcie-phy
+    # FIXME: names when more than 1