[IA64] register memory ranges in a consistent manner

While pursuing and unrelated issue with 64Mb granules I noticed a problem
related to inconsistent use of add_active_range.  There doesn't appear any
reason to me why FLATMEM versus DISCONTIG_MEM should register memory to
add_active_range with different code.  So I've changed the code into a
common implementation.

The other subtle issue fixed by this patch was calling add_active_range in
count_node_pages before granule aligning is performed.  We were lucky with
16MB granules but not so with 64MB granules.  count_node_pages has reserved
regions filtered out and as a consequence linked kernel text and data
aren't covered by calls to count_node_pages.  So linked kernel regions
wasn't reported to add_active_regions.  This resulted in free_initmem
causing numerous bad_page reports.  This won't occur with this patch
because now all known memory regions are reported by
register_active_ranges.

Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Bob Picco <bob.picco@hp.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>