dt-bindings: arm: apple: Add A8 devices

dt-bindings: arm: apple: Add A8 devices

This adds the following apple,t7000 based platforms:

 - iPhone 6
 - iPhone 6 Plus
 - iPad mini 4
 - iPod touch 6
 - Apple TV HD

The remaining HomePod is not supported as part of this patch.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Nick Chan <towinchenmi@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Hector Martin <marcan@marcan.st>