The v4l2_i2c_subdev_init() sets V4L2_SUBDEV_FL_IS_I2C flag in the
subdev->flags.  But this driver overwrites subdev->flags immediately after
calling v4l2_i2c_subdev_init().  So V4L2_SUBDEV_FL_IS_I2C is not set after
all.

This stops breaking subdev->flags and preserves V4L2_SUBDEV_FL_IS_I2C.

Side note: According to the comment in v4l2_device_unregister(), this is
problematic only if the device is platform bus device.  Device tree or
ACPI based devices are not affected.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>