[media] v4l2: correct two SDR format names

U8 and U16LE format human readable names were translated with string
containing emulated word. These strings were taken from msi2500 driver,
where those formats were emulated (after module parameter is set). But
on API correct names should be used, without any special case notes.

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