[ofa-general] [PATCH 0/6 v2] fix pkey change handling and remove the cahce

[Yosef Etigin]

The issue addressed is keeping ipoib interfaces alive despite port's pkey order is changed.
pkey-to-index queries were using a cache. however, the cache might not be up-to-date when
ipoib asks it to resolve a pkey. Therefore must use a direct query. On the other hand, in
build_mlx_header, the pkey query must be atomic. So, the driver will keep its own pkey cache,
which is non blocking and always updated before ipoib is notified of the event.
In addition, remove the pkey delayed initiallization thread, instead start the interface on
pkey change notification.

changes from v1:
 * code style fixes
 * reorganize patches
 * mthca: add gid cache
 * mad: add lmc cache

patch ordering:
1. core: add blockong device queries
2. core,ulp: use bloking queries
3. ipoib: handle pkey event
4. mthca: cache gids and pkeys
5. mad: cache lmc
6. core: remove cache