x86: mmu: allow copying page directory entries with large pages
x86: mmu: allow copying page directory entries with large pages

This changes the assert when a large page is encountered to
copying the page directory entry to the new page directory.
This is needed when a large page entry is generated by
gen_mmu.py. Note that this still asserts when there are entries
of large page at higher level.

Signed-off-by: Daniel Leung <d94e04d205b5962d7873a139ef298b03c1717f72@intel.com>

nashif/zephyr,finikorg/zephyr,nashif/zephyr,galak/zephyr,galak/zephyr,Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,Vudentz/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,Vudentz/zephyr,galak/zephyr