[media] dt3155v4l: code cleanup

- Fix various spelling mistakes
- Whitespace cleanups
- Remove _ioc_ from ioctl names to shorten those names
- Remove bogus ifdef __KERNEL__
- Remove commented out code

No actual code is changed in this patch.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>