docs: net: dpio-driver.rst: fix two codeblock warnings

Documentation/networking/device_drivers/freescale/dpaa2/dpio-driver.rst:43: WARNING: Definition list ends without a blank line; unexpected unindent.
    Documentation/networking/device_drivers/freescale/dpaa2/dpio-driver.rst:63: WARNING: Unexpected indentation. looking for now-outdated files... none found

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/networking/device_drivers/freescale/dpaa2/dpio-driver.rst

@@ -39,8 +39,7 @@ The Linux DPIO driver consists of 3 primary components--
 
    DPIO service-- provides APIs to other Linux drivers for services
 
-   QBman portal interface-- sends portal commands, gets responses
+   QBman portal interface-- sends portal commands, gets responses::
-::
 
           fsl-mc          other
            bus           drivers
@@ -60,6 +59,7 @@ The Linux DPIO driver consists of 3 primary components--
 
 The diagram below shows how the DPIO driver components fit with the other
 DPAA2 Linux driver components::
+
                                                    +------------+
                                                    | OS Network |
                                                    |   Stack    |