Documentation: dpaa2: Use correct heading adornment

Add overline heading adornment to document title in order to comply
with kernel doc requirements.

Fixes: 60b9131 staging: fsl-mc: Convert documentation to rst format

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/networking/dpaa2/overview.rst b/Documentation/networking/dpaa2/overview.rst
index 79fede4..d638b5a 100644
--- a/Documentation/networking/dpaa2/overview.rst
+++ b/Documentation/networking/dpaa2/overview.rst
@@ -1,5 +1,6 @@
 .. include:: <isonum.txt>
 
+=========================================================
 DPAA2 (Data Path Acceleration Architecture Gen2) Overview
 =========================================================