Pull ieee80211_ratectl_node_init() calls from drivers into net80211.
This fixes hostap mode for at least ral(4) and run(4), because there is
no sufficient call into drivers which could be used initialize the node
related ratectl variables.

Approved by:	re (bz)

Instead of using the AMRR ratectl algo as default for drivers which have
the IEEE80211_C_RATECTL flag set, default to NONE for all drivers. Only if
a driver calls ieee80211_ratectl_init() check if the NONE algo is still
selected and try to use AMRR in that case. Drivers are still free to use
any other algo by calling ieee80211_ratectl_set() prior to the
ieee80211_ratectl_init() call.

After this change it is now safe to assume that a ratectl algo is always
available and selected, which renders the IEEE80211_C_RATECTL flag pretty
much useless. Therefore revert r211314 and 211546.

  Add new tunable 'net.link.ifqmaxlen' to set default send interface
  queue length. The default value for this parameter is 50, which is
  quite low for many of today's uses and the only way to modify this
  parameter right now is to edit if_var.h file. Also add read-only
  sysctl with the same name, so that it's possible to retrieve the
  current value.

  Fixes a bug for LP PHY that some frames have 2 padding bytes at the
  start so we should adjust the mbuf if the driver is running in PIO
  mode.  Now it should work well with WPA authentication and association
  for LP PHY devices.

  Tested by:    Warren Block <wblock at wonkity.com>

  Fixes a mistake to calculate CALC_COEFF2() value that tmp[3] is
  used even if it's unreachable.

  PR:		kern/144505
  Submitted by:	Henning Petersen <henning.petersen at t-online dot de>

Introduce IEEE80211_C_RATECTL, drivers which use the ratectl framework
should set this capability. Initialize ni_txrate after txparams have
been setup. Some drivers calculate various things prior to association
based on ni_txrate and rely on it being nonzero.

PR:		kern/149185

  - fixes a bug that it didn't initialize the ratectl after association;
    so ni_txrate returned 0 which is a invalid result.
  - The fourth argument of ieee80211_ratectl_tx_complete() could be not
    NULL.

  Reported by:  Gustau P?rez <gperez at entel.upc.edu>
  Tested by:    Gustau P?rez <gperez at entel.upc.edu>,
                Ian FREISLICH <ianf at clue.co.za>

    r206416, r206417, r206418, r206418:

net80211 ratectl framework.

  ifp->if_ipackets++ when RX packet interrupts are occurred.

  enables S/W beacon miss handler.

  Reported by:	imp