dt-bindings: gnss: add w2sg0004 compatible string

Add w2sg0004 compatible string since devices without wakeup
pins are now supported.
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

Documentation/devicetree/bindings/gnss/sirfstar.txt

@@ -12,6 +12,7 @@ Required properties:
 
 			"fastrax,uc430"
 			"linx,r4"
+			"wi2wi,w2sg0004"
 			"wi2wi,w2sg0008i"
 			"wi2wi,w2sg0084i"