Before, the driver was always doing the dynamic allocation due to
i2c_add_adapter(). So there could not have been a system that relied on
consistent i2c bus numbering. Even between reboots bus numbering could change.

The systems that did set pdev->id and were expecting a consistent i2c bus
numbering were broken to begin with.

This patch won’t break any existing systems or cause regressions.

Great, now please add that to the commit message. These are the sort
of things reviewers want to know, is a change going to cause
regressions. If you have done your homework, mentioning it in the
commit message will help avoid the questions being asked.

       Andrew