dt-bindings: i2c: apple,i2c: Add apple,t6000-i2c compatible

This block is compatible with t8103, so just add the new per-SoC
compatible under apple,i2c.

Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hector Martin <marcan@marcan.st>