arm64: dts: apple: Add A10X devices

Add DTS files for the A10X SoC and the following devices based on it:

- Apple TV 4K
- iPad Pro (2nd Generation) (10.5 Inch)
- iPad Pro (2nd Generation) (12.9 Inch)

Signed-off-by: Konrad Dybcio <konradybcio@kernel.org>
[Nick: SMP, m1n1 and Apple TV 4K support, uart interrupt and pinctrl fixes]
Co-developed-by: Nick Chan <towinchenmi@gmail.com>
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>