configure.ac: add a check for linux/mempolicy.h
testcases/kernel/hotplug/...:
- Enable memory hotplug build and install
- Cordon off mempolicy / numa dependent logic on systems where it isn't available for compile / linux.
- Remove ad hoc / mostly incorrect move_mempages logic.

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
diff --git a/configure.ac b/configure.ac
index eeee355..52f3381 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,6 +36,7 @@
     mm.h \
     pthread.h \
     linux/genetlink.h \
+    linux/mempolicy.h \
     linux/module.h \
     linux/netlink.h \
     sys/acl.h \