ARM: dts: qcom: dt-bindings: Document qcom,sleep-clk-bcr quirk

Newly added optional quirk "qcom,sleep-clk-bcr" adds delay of
200-250us after deasserting the USB3 BCR. This is needed on
some targets where sleep clk is used for BCR demet.

Change-Id: I88370838c29f679f2d2d90f565d3884d48bcdff2
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>

bindings/usb/qcom,dwc-usb3-msm.yaml

@@ -104,6 +104,10 @@ properties:
     description: disable cm l1.
     type: boolean
 
+  qcom,sleep-clk-bcr:
+    description: If present, use additional delay after BCR.
+    type: boolean
+
   qcom,core-clk-rate:
     description: Core/Master clock rate.
     $ref: /schemas/types.yaml#/definitions/uint32