Use the physical device rather than the i2c adapter as the reference
device when loading firmwares. This will prevent the sysfs name
collision with i2c-dev that has been reported many times.

I may have missed other drivers which need the same fix.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>