mei: drop the TODO from samples

The TODO file is not relevant anymore and it's just a leftover from
the time the driver was in the staging tree.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>