docs: soundwire: fix some identation at stream.rst

Currently, sphinx emits one warning on this file:

	Documentation/driver-api/soundwire/stream.rst:522: WARNING: Block quote ends without a blank line; unexpected unindent.

That's due to some extra spaces before the title of a chapter.

Yet, the list afterwards is missing identation.

So, address both issues.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/eddde9f8d121e27d7968b3d747064e16de8bec4f.1599660067.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/driver-api/soundwire/stream.rst

@@ -518,10 +518,10 @@ typically called during a dailink .shutdown() callback, which clears
 the stream pointer for all DAIS connected to a stream and releases the
 memory allocated for the stream.
 
-  Not Supported
+Not Supported
 =============
 
 1. A single port with multiple channels supported cannot be used between two
-streams or across stream. For example a port with 4 channels cannot be used
-to handle 2 independent stereo streams even though it's possible in theory
-in SoundWire.
+   streams or across stream. For example a port with 4 channels cannot be used
+   to handle 2 independent stereo streams even though it's possible in theory
+   in SoundWire.