[PATCH] i2c: Drop i2c_driver.flags, 1 of 3

The I2C_DF_DUMMY flag is gone since 2.5.70, it's about time to
drop all ifdef'd out references thereto.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>