Fix spelling for parenthesis in dmatest documentation.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[ jc: did s/parenthesis/parentheses/ and reflowed ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Make dmatest.rst indeed reST compatible.
Achieve this by fixing several formatting issues.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The documentation is not so clear for newbies in a sense of what type of the
channels are supported by it.

Clarify this by adding a note at the preamble of the documentation.

Reported-by: "Zhu, Tony" <tony.zhu@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

This converts and moves dmatest file with some format
changes for RST style

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>