i2c: Legacy i2c drivers shouldn't issue uevents

Prevent legacy drivers from issuing uevents for device creation/removal,
so that userspace can't cause modprobing loops for them.  This became a
problem for some legacy PC drivers.  I can't easily see it becoming an
issue with I2C legacy drivers, but consistency-in-paranoia seems likely
to be a good thing here.  For usable i2c-level driver model uevents, just
switch to a new-style driver.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>