Sometimes the memory to be allocated is not at the end of an entry,
that means we have to break one enty into 2 smaller entries, there
are two ways to add the new entry to hv_e820, adds to the end or
insert it.
The initial e820 table is ordered, that's why the e820_alloc_memory
interface asssum all entries was sorted, but add new entry to the
end will break the orde of hv_e820.
So we use insert_e820_entry to replace the add_e820_entry, the new
interfeac will keep the orde and users do not need sort again after
alloc region
Tracked-On: #6690
Acked-by: Anthony Xu <anthony.xu@intel.com>
Signed-off-by: Chenli Wei<chenli.wei@linux.intel.com>