dt-bindings: PCI: tegra194: Fix PCIe endpoint node names

As defined by Documentation/devicetree/bindings/pci/pci-ep.yaml,
PCIe endpoints match this pattern:

properties:
$nodename:
pattern: "^pcie-ep@"

Change the existing ones in the DT bindings examples to avoid warnings
during DT bindings validation.

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Thierry Reding <[e-mail]>

Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie.txt

···
 Tegra194 EP mode:
 -----------------
 
-	pcie_ep@141a0000 {
+	pcie-ep@141a0000 {
 		compatible = "nvidia,tegra194-pcie-ep", "snps,dw-pcie-ep";
 		power-domains = <&bpmp TEGRA194_POWER_DOMAIN_PCIEX8A>;
 		reg = <0x00 0x141a0000 0x0 0x00020000   /* appl registers (128K)      */