dm: i2c: Implement 'i2c bus' command for driver model

This command was missed in the conversion. Add it back for driver model.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Heiko Schocher <hs@denx.de>
1 file changed