arm64: dts: apple: Add T2 devices

arm64: dts: apple: Add T2 devices

Add DTS files for the T2 SoC and the following devices based on it:

- Apple T2 MacBookPro15,2 (j132)
- Apple T2 iMacPro1,1 (j137)
- Apple T2 MacBookAir8,2 (j140a)
- Apple T2 MacBookAir8,1 (j140k)
- Apple T2 MacBookPro16,1 (j152f)
- Apple T2 MacPro7,1 (j160)
- Apple T2 Macmini8,1 (j174)
- Apple T2 iMac20,1 (j185)
- Apple T2 iMac20,2 (j185f)
- Apple T2 MacBookPro15,4 (j213)
- Apple T2 MacBookPro16,2 (j214k)
- Apple T2 MacBookPro16,4 (j215)
- Apple T2 MacBookPro16,3 (j223)
- Apple T2 MacBookAir9,1 (j230k)
- Apple T2 MacBookPro15,1 (j680)
- Apple T2 MacBookPro15,3 (j780)

The Apple T2 is an A10-based security chip found on some Intel Macs
from 2017 onwards. On models with a touchbar, the touchbar's
display is wired to it. These devices have no offical names, the
naming scheme is from libirecovery.

Signed-off-by: Nick Chan <towinchenmi@gmail.com>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Sven Peter <sven@svenpeter.dev>