ice: Fix state bits on LLDP mode switch

DCBX_CAP bits were not being adjusted when switching
between SW and FW controlled LLDP.

Adjust bits to correctly indicate which mode the
LLDP logic is in.

Fixes: b94b013e ("ice: Implement DCBNL support")
Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>