MFC r202821-202822.

MFC r202821-202822.

r202821:
  Fix a long standing ASF heartbeat sending bug. The initial
  implementation of heartbeat interval was 2 but there was typo which
  caused the heartbeat is sent approximately every 5 seconds. This
  caused unintended controller reset by firmware because firmware
  thought OS was crashed.

  Submitted by:	Floris Bos < info <> je-eigen-domein dot nl >
  Tested by:	Andrzej Tobola < ato <> iem dot pw dot edu dot pl >

r202822:
  Use new handshake command for BCM5750 or new controllers.

git-svn-id: svn://svn.freebsd.org/base/stable/8@205284 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f