dt-bindings: arm: add compatible for Forlinx OKA40i-C and FETA40i-C

The FETA40i-C is a SoM by Forlinx based on the Allwinner R40/A40i SoC.
The OKA40i-C is a carrier/development board by the same company based on
this SoM.

This patch adds compatible strings for these two devices in preparation for
the next patch containing a devicetree for them.
Signed-off-by: Ivan Uvarov <i.uvarov@cognitivepilot.com>

 1 file changed, 6 insertions(+)
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210407111428.3755684-5-i.uvarov@cognitivepilot.com

Documentation/devicetree/bindings/arm/sunxi.yaml

@@ -224,6 +224,12 @@ properties:
           - const: empire-electronix,m712
           - const: allwinner,sun5i-a13
 
+      - description: Forlinx OKA40i-C Development board
+        items:
+          - const: forlinx,oka40i-c
+          - const: forlinx,feta40i-c
+          - const: allwinner,sun8i-r40
+
       - description: FriendlyARM NanoPi A64
         items:
           - const: friendlyarm,nanopi-a64