dt-bindings: net: dwmac-meson: Add a compatible string for G12A onwards

Amlogic Meson G12A, G12B and SM1 have the same (at least as far as we
know at the time of writing) PRG_ETHERNET glue register implementation.
This implementation however is slightly different from AXG as it now has
an undocument "auto cali idx val" register in PRG_ETH1[17:16] which
seems to be related to RGMII Ethernet.

Add a compatible string for G12A and newer so the new registers can be
used.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/amlogic,meson-dwmac.yaml

@@ -22,6 +22,7 @@ select:
           - amlogic,meson8m2-dwmac
           - amlogic,meson-gxbb-dwmac
           - amlogic,meson-axg-dwmac
+          - amlogic,meson-g12a-dwmac
   required:
     - compatible
 
@@ -36,6 +37,7 @@ allOf:
               - amlogic,meson8m2-dwmac
               - amlogic,meson-gxbb-dwmac
               - amlogic,meson-axg-dwmac
+              - amlogic,meson-g12a-dwmac
 
     then:
       properties:
@@ -95,6 +97,7 @@ properties:
           - amlogic,meson8m2-dwmac
           - amlogic,meson-gxbb-dwmac
           - amlogic,meson-axg-dwmac
+          - amlogic,meson-g12a-dwmac
     contains:
       enum:
         - snps,dwmac-3.70a