docs: def activate_backup_image(reset=False):
      '''
      Activates the firmware backup image.
  
      CLI Example:
  
      Args:
          reset(bool): Reset the CIMC device on activate.
  
      .. code-block:: bash
  
          salt '*' cimc.activate_backup_image
          salt '*' cimc.activate_backup_image reset=True
  
      '''
  
      dn = "sys/rack-unit-1/mgmt/fw-boot-def/bootunit-combined"
  
      r = "no"
  
      if reset is True:
          r = "yes"
  
      inconfig = """<firmwareBootUnit dn='sys/rack-unit-1/mgmt/fw-boot-def/bootunit-combined'
      adminState='trigger' image='backup' resetOnActivate='{0}' />""".format(r)
  
      ret = __proxy__['cimc.set_config_modify'](dn, inconfig, False)
  
      return ret