Implement the port_modify() device method for mthca using the SET_IB firmware
command.  In particular this allows changing the port capability mask.
Signed-off-by: Roland Dreier <roland@topspin.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>