ice: refactor "last" segment of DDP pkg

Add ice_ddp_send_hunk() that buffers "sent FW hunk" calls to AQ in order
to mark the "last" one in more elegant way. Next commit will add even
more complicated "sent FW" flow, so it's better to untangle a bit before.

Note that metadata buffers were not skipped for NOT-@indicate_last
segments, this is fixed now.

Minor:
 + use ice_is_buffer_metadata() instead of open coding it in
   ice_dwnld_cfg_bufs();
 + ice_dwnld_cfg_bufs_no_lock() + dependencies were moved up a bit to have
   better git-diff, as this function was rewritten (in terms of git-blame)

CC: Paul Greenwalt <paul.greenwalt@intel.com>
CC: Dan Nowlin <dan.nowlin@intel.com>
CC: Ahmed Zaki <ahmed.zaki@intel.com>
CC: Simon Horman <horms@kernel.org>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>