- Add interrupt handlers for Master Enable events from PFs
  and Master Enable events from VFs of AF
- Master Enable is required for the MSIX delivery to work
- Master Enable bit trap handler doesn't have to do any anything
  other than clearing the TRPEND bit, since the enable/disable
  requirements are already taken care using mbox requests/flr handler.
Signed-off-by: Linu Cherian <lcherian@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>