i2c: Congatec Board Controller i2c bus driver

Add i2c support for the Congatec Board Controller.

The Board Controller has two i2c busses, a General Purpose bus and a Power
Management bus.

Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
Link: https://lore.kernel.org/r/20241001-congatec-board-controller-v3-3-39ceceed5c47@bootlin.com


Signed-off-by: Lee Jones <lee@kernel.org>