mlx4_core: initial header-file changes for SRIOV support

These changes will not affect module operation as yet. They
are only to get some structs and enums in place for use by
subsequent patches (making those smaller).

Added here:
* sriov state structs and inlines (mlx4_is_master/slave/mfunc)
* comm-channel and vhcr support structures
* enum values for new FW and comm-channel virtual commands
  (i.e., commands, passed via the comm channel to the PF-driver).
* prototypes for many command wrapper functions (used by the
  PF context for processing FW commands passed to it by the VFs).
* struct mlx4_eqe is moved from eq.c to mlx4.h (it will be used
  by other mlx4_core source files).

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>