staging: comedi: add CMDF_ROUND_... as synonyms for TRIG_ROUND_...

staging: comedi: add CMDF_ROUND_... as synonyms for TRIG_ROUND_...

The `TRIG_ROUND_...` macros are some of the values that can be OR-ed
into the `flags` member of `struct comedi_cmd`.  They may influence the
rounding of sample timings during operation of the asynchronous command.

The names are a bit of a left-over from earlier times.  It would be
better to use the names `CMDF_ROUND_...` to match various other command
flags.

Define `CMDF_ROUND_MASK`, `CMDF_ROUND_NEAREST`, `CMDF_ROUND_DOWN`,
`CMDF_ROUND_UP` and `CMDF_ROUND_UP_NEXT` with the same numeric values as
`TRIG_ROUND_MASK`, `TRIG_ROUND_NEAREST`, `TRIG_ROUND_DOWN`,
`TRIG_ROUND_UP` and `TRIG_ROUND_UP_NEXT`, and redefine the
`TRIG_ROUND_...` macros as synonyms of the `CMDF_ROUND_...` macros.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>