dt-bindings: soc: qcom: wcnss: Add firmware-name property

The WCNSS needs firmware which differs between platforms, and possibly
boards. Add a new property "firmware-name" to allow the DT to specify
the platform/board specific path to this firmware file.
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Aníbal Limón <anibal.limon@linaro.org>
Link: https://lore.kernel.org/r/20210312003318.3273536-2-bjorn.andersson@linaro.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Documentation/devicetree/bindings/soc/qcom/qcom,wcnss.txt

@@ -24,6 +24,13 @@ block and a BT, WiFi and FM radio block, all using SMD as command channels.
 		    "qcom,riva",
 		    "qcom,pronto"
 
+- firmware-name:
+	Usage: optional
+	Value type: <string>
+	Definition: specifies the relative firmware image path for the WLAN NV
+		    blob. Defaults to "wlan/prima/WCNSS_qcom_wlan_nv.bin" if
+		    not specified.
+
 = SUBNODES
 The subnodes of the wcnss node are optional and describe the individual blocks in
 the WCNSS.