fix invalid installs of docs/man and config into /usr/local

--- xen-4.2.2-orig/tools/Makefile	2013-04-23 18:42:55.000000000 +0200
+++ xen-4.2.2/tools/Makefile	2013-07-29 17:01:33.764093405 +0200
@@ -199,6 +199,9 @@
 		--bindir=$(LIBEXEC) \
 		--datadir=$(SHAREDIR)/qemu-xen \
 		--disable-kvm \
+		--mandir=/usr/share/man \
+		--docdir=/usr/share/doc/xen \
+		--sysconfdir=/etc \
 		--python=$(PYTHON) \
 		$(IOEMU_CONFIGURE_CROSS); \
 	$(MAKE) all