board/BuR/*: replace maintainer of BuR boards

Since I'm leaving the company with end of June, the maintainership will
be transferred to Wolfgang Wallner.

Signed-off-by: Hannes Schmelzer <hannes.schmelzer@br-automation.com>
Signed-off-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
diff --git a/board/BuR/brppt2/MAINTAINERS b/board/BuR/brppt2/MAINTAINERS
index a1b5bd4..fe65188 100644
--- a/board/BuR/brppt2/MAINTAINERS
+++ b/board/BuR/brppt2/MAINTAINERS
@@ -1,5 +1,5 @@
 BUR_PPT2 BOARD
-M:	Hannes Schmelzer <hannes.schmelzer@br-automation.com>
+M:	Wolfgang Wallner <wolfgang.wallner@br-automation.com>
 S:	Maintained
 F:	board/BuR/brppt2/
 F:	include/configs/brppt2.h