MAINTAINERS: Switch SUPERH to Supported.

Apparently the SH entry ought to be Supported instead of Maintained,
given the suble difference in terminology. Though it's been this way
for years now, thanks to Renesas.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

MAINTAINERS

@@ -3968,7 +3968,7 @@ M:	lethal@linux-sh.org
 L:	linux-sh@vger.kernel.org
 W:	http://www.linux-sh.org
 T:	git kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6.git
-S:	Maintained
+S:	Supported
 
 SUN3/3X
 P:	Sam Creasey