dt-bindings: mtd: ti, gpmc-nand: Add compatible for AM64 NAND

AM64 SoC contains the GPMC NAND controller. Add compatible for it.

Cc: Rob Herring <[e-mail]>
Signed-off-by: Roger Quadros <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Miquel Raynal <[e-mail]>
Link: https://lore.kernel.org/linux-mtd/[e-mail]

Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml

···
 
 properties:
   compatible:
-    const: ti,omap2-nand
+    items:
+      - enum:
+          - ti,am64-nand
+          - ti,omap2-nand
 
   reg:
     maxItems: 1