MAINTAINERS: Update HVC file patterns

Commit 728674a7
("tty: move hvc drivers to drivers/tty/hvc/")
moved the files, update the patterns as appropriate.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>