Remove the #ifdef OFED from the 20 byte mac in struct llentry.

With this change it is now possible to build the entire infiniband
stack as modules and load it dynamically including IP over IB.
Update the MEM_UOP_RETIRED PMC operation for sandy bridge and sandy
bridge Xeon.

Summary: These are PEBS events but they're also available as normal
counter/sample events.  The source table (Table 19-2) lists the
base versions (LOAD, STLB_MISS, SPLIT, ALL) but it says they must
be qualified with other values.  This particular commit fleshes
out those umask values.

Source:

* Linux; SDM June 2013, Volume 3B, Table 19-2 and 18-21.

Tested:

* Sandy Bridge (non-Xeon)