MAINTAINERS: add lib/livepatch to LIVE PATCHING

Add lib/livepatch to list of livepatching F: patterns in MAINTAINERS.

Suggested-by: Jiri Kosina <jikos@kernel.org>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>