media: drivers/staging/media: don't set description for ENUM_FMT
The V4L2 core sets the format description and flags for the driver in order
to ensure consistent naming.
So drop the strscpy of the description in drivers. Also remove any
description strings in driver-internal structures since those are
no longer needed.
Note that bcm2835-camera.c: the formats array still stores the flags
field for compressed formats since that information is used elsewhere
in the driver. But enum_fmt doesn't use it anymore, since the core
will set the COMPRESSED flag correctly.