Apple M1 has at least 5 i2c controllers. i2c0, i2c1 and i2c3 are used
on all M1 Mac devices. The 2020 Mac Mini uses i2c2 and the 13-inch
MacBook Pro uses i2c2 and i2c4.
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Tested-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Hector Martin <marcan@marcan.st>