memory hotadd 4/7: Setup frametable for hot-added memory

memory hotadd 4/7: Setup frametable for hot-added memory

We can't use alloc_boot_pages for memory hot-add, so change it to use
the pages range passed in.

One changes need notice is, when memory hotplug needed, we have to
setup initial frametable as pdx index (i.e. the pdx_gorund_valid)
aligned, to make sure mfn_valid() still works after the max_page is
not maximum anymore.

Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>