dt-bindings: vendor-prefixes: Add apple prefix

This is different from the legacy AAPL prefix used on PPC, but
consensus is that we prefer `apple` for these new platforms.

Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Hector Martin <[e-mail]>

Documentation/devicetree/bindings/vendor-prefixes.yaml

···
     description: Anvo-Systems Dresden GmbH
   "^apm,.*":
     description: Applied Micro Circuits Corporation (APM)
+  "^apple,.*":
+    description: Apple Inc.
   "^aptina,.*":
     description: Aptina Imaging
   "^arasan,.*":