[PATCH] IB/mthca: Align FW command mailboxes to 4K

Future versions of Mellanox HCA firmware will require command mailboxes to be
aligned to 4K.  Support this by using a pci_pool to allocate all mailboxes.
This has the added benefit of shrinking the source and text of mthca.

Signed-off-by: Roland Dreier <roland@topspin.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>