i40e: missing priorities for any QoS traffic

This patch fixes reading f/w LLDP agent status at DCB init time.
It's done by removing direct NVM reading in i40e_update_dcb_config()
and checking whether f/w LLDP agent is disabled via
I40E_FLAG_DISABLE_FW_LLDP flag in i40e_init_pf_dcb(). The function
i40e_update_dcb_config() in i40e_main.c is a temporary solution which
will be later renamed to i40e_init_dcb() in the i40e_dcb module. Also
logging was extended to make visible if f/w LLDP agent is running or not
and always log a message when DCB was not initialized. Without this
patch for new f/w versions f/w LLDP agent status was always read
from NVM as disabled and DCB initialization failed without
clear reason in logs.

Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>