P_Key change and guid change events are not of interest to all slaves,
but only to those slaves which "see" the table slots whose contents
have change.

For example, if the guid at port 1, index 5 has changed in the PPF, we
wish to propagate the gid-change event only to the function which has
that guid index mapped to its port/guid table (in this case it is
slave #5). Other functions should not get the event, since the event
does not affect them.

Similarly with P_Keys -- P_Key change events are forwarded only to
slaves which have that P_Key index mapped to their virtual P_Key table.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>