ntb: ntb_hw_intel: init peer_addr in struct intel_ntb_dev

The peer_addr member of intel_ntb_dev is not set, therefore when
acquiring ntb_peer_db and ntb_peer_spad we only get the offset rather
than the actual physical address. Adding fix to correct that.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>