Input: appletouch - add Johannes Berg as maintainer

After the last patch that broke appletouch for powerbooks again I'd like
to take over maintainership of this driver to make sure it doesn't break
again in the future.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

MAINTAINERS

@@ -398,6 +398,12 @@ P:	Arnaldo Carvalho de Melo
 M:	acme@ghostprotocols.net
 S:	Maintained
 
+APPLETOUCH TOUCHPAD DRIVER
+P:	Johannes Berg
+M:	johannes@sipsolutions.net
+L:	linux-input@atrey.karlin.mff.cuni.cz
+S:	Maintained
+
 ARC FRAMEBUFFER DRIVER
 P:	Jaya Kumar
 M:	jayalk@intworks.biz