dt-bindings: remoteproc: qcom,wcnss: Add qcom,wcn3660b compatible

WCN3660B is a variant of WCN3660, but with the same regulator
requirements as WCN3620/WCN3680. Add a new qcom,wcn3660b compatible
to describe it from device trees.
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210106102134.59801-2-stephan@gerhold.netSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Documentation/devicetree/bindings/remoteproc/qcom,wcnss-pil.txt

@@ -80,6 +80,7 @@ and its resource dependencies. It is described by the following properties:
 	Definition: must be one of:
 		    "qcom,wcn3620",
 		    "qcom,wcn3660",
+		    "qcom,wcn3660b",
 		    "qcom,wcn3680"
 
 - clocks: