dt-bindings: PCI: brcmstb: New prop 'aspm-no-l0s'

For various reasons, one may want to disable the ASPM L0s
capability.

Link: https://lore.kernel.org/r/20200507201544.43432-4-james.quinlan@broadcom.com
Signed-off-by: Jim Quinlan <jquinlan@broadcom.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml

@@ -56,6 +56,8 @@ properties:
     description: Indicates usage of spread-spectrum clocking.
     type: boolean
 
+  aspm-no-l0s: true
+
 required:
   - reg
   - dma-ranges