MAINTAINERS: add file patterns to UCLINUX FOR RENESAS H8/300

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>