x86: MMU: Configure page tables entries for memory domain in swap.

During swap the required page tables are configured. The outgoing
thread's memory domain pages are reset and the incoming thread's
memory domain is loaded. The pages are configured if userspace
is enabled and if memory domain has been initialized before
calling swap.

GH-3852

Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>