Staging: olpc_dcon: change to msleep to usleep_range

The resolution of msleep is related to HZ, so with HZ set to
100 any msleep of less then 10ms will become ~10ms. This is
not what we want. Use usleep_range to get more control of
what is happening here.

Signed-off-by: Jens Frederich <jfrederich@gmail.com>
staging: olpc_dcon: provide detailed FB_OLPC_DCON help section

The FB_OLPC_DCON help section is to short according to checkpatch.pl.
We want more information about the controller type, its task, its video
pipeline position and so on.

There are no style issues, remove checkpatch.pl TODO entry.

Signed-off-by: Jens Frederich <jfrederich@gmail.com>