Probe and remove methods are now defined at bus level. No more need to
redefine them at driver level in i2c-isa.

This lets us get rid of these annoying messages:
Driver 'it87-isa' needs updating - please use bus_type methods

Thanks to Nicolas Mailhot for reporting the problem and testing the fix.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>