dt-bindings: vendor: add vendor prefix for LiteX

Add vendor prefix for LiteX SoC builder.
Signed-off-by: Filip Kokosinski <fkokosinski@antmicro.com>
Signed-off-by: Mateusz Holenko <mholenko@antmicro.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>

Documentation/devicetree/bindings/vendor-prefixes.yaml

@@ -601,6 +601,8 @@ patternProperties:
     description: Linux-specific binding
   "^linx,.*":
     description: Linx Technologies
+  "^litex,.*":
+    description: LiteX SoC builder
   "^lltc,.*":
     description: Linear Technology Corporation
   "^logicpd,.*":