dt-bindings: net: snps, dwmac: update reg minItems maxItems

The Amlogic Meson DWMAC glue bindings needs a second reg cells for the
glue registers, thus update the reg minItems/maxItems to allow more
than a single reg cell.

Also update the allwinner,sun7i-a20-gmac.yaml derivative schema to specify
maxItems to 1.

Signed-off-by: Neil Armstrong <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Acked-by: Maxime Ripard <[e-mail]>
Reviewed-by: Martin Blumenstingl <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/devicetree/bindings/net/allwinner,sun7i-a20-gmac.yaml

···
   compatible:
     const: allwinner,sun7i-a20-gmac
 
+  reg:
+    maxItems: 1
+
   interrupts:
     maxItems: 1
 

Documentation/devicetree/bindings/net/snps,dwmac.yaml

···
         - snps,dwxgmac-2.10
 
   reg:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
 
   interrupts:
     minItems: 1