i40e: rework debug messages for NVM update

Rework the debug messages in the NVM update state machine so that we can
turn them on and off dynamically rather than forcing a recompile/reload.

These can now be turned on with something like:
	ethtool -s eth1 msglvl 0xf000008f
and off with:
	ethtool -s eth1 msglvl 0xf000000f

The high 0xf0000000 gets the driver's attention that we want to change the
internal debug flags, and the 0x80 bit is the NVM debug.

Change-ID: I5efb9039400304b29a0fd6ddea3f47bb362e6661
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>