MFC r273247:
 Fix the watchdog/watchdog man pages.

 The default timeout is 128 seconds.
MFC r273248:
 AM335x FDT: add an entry for the watchdog.
MFC r273256:
 AM335X FDT: use the omap3-wdt string for compatibility with Linux.
MFC r273257:
 Add a driver for the TI watchdog.

 The TI watchdog timer is present on BeagleBone's.  Since 2014, U-Boot
 has been booting the BeagleBone with the watchdog enabled.  We need
 to
 disable it on boot to avoid a spurious reset.
 The timer isn't exactly precise, but it will do as a watchdog.  This
 is also a reflection of the watchdog(9) API.

 In the future, we could handle interrupts, but the watchdog(9) API
 needs to be a bit smarter before that can happen.
MFC r273258:
 Make the ti_mbox and ti_pruss drivers optional.
MFC r273261:
 Remove an unused mutex.
MFC r273448:
Fix the kernel panic in hostap mode.
rvp->beacon_mbuf was NULL in run_update_beacon().

PR:	189405
Submitted by:	Gabor Simon <gabor.simon75 at gmail.com>
MFC r268633, r271046:

  Fixes and enhancements for the if_cgem driver...

  - miibus fixes as suggested by Yonghyeon Pyun.
  - enable VLAN MTU support.
  - fix a few WITNESS complaints in cgem_attach().
  - have cgem_attach() properly init the ifnet struct before calling
    mii_attach() to fix panic when using e1000phy.
  - fix ethernet address changing.
  - fix transmit queue overflow handling.
  - tweak receive queue handling to reduce receive overflows.
  - bring out MAC statistic counters to sysctls.
  - add e1000phy to config file.
  - implement receive hang work-around described in reference guide.
  - change device name from if_cgem to cgem to be consistent with other
    interfaces.

  Fix the Zedboard/Zynq ethernet driver to handle media speed changes so
  that it can connect to switches at speeds other than 1gb.
Merge remote-tracking branch 'freebsd/stable/10' into freebsd10