ixgbe: fix qv_lock_napi call in ixgbe_napi_disable_all

ixgbe_napi_disable_all calls napi_disable on each queue, however the busy
polling code introduced a local_bh_disable()d context around the napi_disable.
The original author did not realize that napi_disable might sleep, which would
cause a sleep while atomic BUG. In addition, on a single processor system, the
ixgbe_qv_lock_napi loop shouldn't have to mdelay. This patch adds an
ixgbe_qv_disable along with a new IXGBE_QV_STATE_DISABLED bit, which it uses to
indicate to the poll and napi routines that the q_vector has been disabled. Now
the ixgbe_napi_disable_all function will wait until all pending work has been
finished and prevent any future work from being started.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: Alexander Duyck <alexander.duyck@intel.com>
Cc: Hyong-Youb Kim <hykim@myri.com>
Cc: Amir Vadai <amirv@mellanox.com>
Cc: Dmitry Kravkov <dmitry@broadcom.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>