The Xiaomi Mi Router 4A (100M) and 4C are relatively similar in
their specs. Create a shared DTSI for them.
Partitions are split in preparation for Mi Router 4AC.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Signed-off-by: maurerr <mariusd84@gmail.com>
