edac, highbank: Add MAINTAINERS entry

So taking over maintainership for the EDAC highbank driver.
Signed-off-by: NRobert Richter <rric@kernel.org>
Acked-by: NBorislav Petkov <bp@suse.de>
Acked-by: NRob Herring <rob.herring@calxeda.com>

MAINTAINERS

@@ -3047,6 +3047,14 @@ W:	bluesmoke.sourceforge.net
 S:	Maintained
 F:	drivers/edac/amd64_edac*
 
+EDAC-CALXEDA
+M:	Doug Thompson <dougthompson@xmission.com>
+M:	Robert Richter <rric@kernel.org>
+L:	linux-edac@vger.kernel.org
+W:	bluesmoke.sourceforge.net
+S:	Maintained
+F:	drivers/edac/highbank*
+
 EDAC-CAVIUM
 M:	Ralf Baechle <ralf@linux-mips.org>
 M:	David Daney <david.daney@cavium.com>