arm: apple: Add M1 Pro/Max support

arm: apple: Add M1 Pro/Max support

Choose the memory map based on the compatible property from the
device tree passed to us by m1n1. Since DRAM on the M1 Pro/Max
starts at a different address avoid hardcoding the top of usable
memory. Also make sure that the addresses entered into the memory
map are page aligned such that we don't crash in dcache_enable().

Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Tested on: Macbook M1 Max
Tested-by: Janne Grunau <j@jannau.net>