ixgbe: clean up ipsec defines

Clean up the ipsec/macsec descriptor bit definitions to match the rest
of the defines and file organization.  Also recognise the bit-definition
overlap in the error mask macro.

Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>