board: synquacer: developerbox: add myself as maintainer

Add myself as maintainer for SynQuacer Developerbox,
as I'm currently working on it.
This commit also removes Jassi from maintainer since he
no longer has a Developerbox.

Cc: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Masahisa Kojima <kojima.masahisa@socionext.com>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
diff --git a/board/socionext/developerbox/MAINTAINERS b/board/socionext/developerbox/MAINTAINERS
index c6d4f27..ca606c8 100644
--- a/board/socionext/developerbox/MAINTAINERS
+++ b/board/socionext/developerbox/MAINTAINERS
@@ -1,5 +1,5 @@
 DEVELOPER BOX
-M:	Jassi Brar <jaswinder.singh@linaro.org>
+M:	Masahisa Kojima <kojima.masahisa@socionext.com>
 S:	Maintained
 F:	arch/arm/dts/synquacer-*
 F:	board/socionext/developerbox/*