igc: Clean RX descriptor error flags

i225 advanced receive descriptor doesn't have the following extend error
bits: CE, SE, SEQ, CXE. In addition to that, the bit TCPE is called L4E
in the datasheet.

Clean up the code accordingly, and get rid of the macro
IGC_RXDEXT_ERR_FRAME_ERR_MASK since it doesn't make much sense anymore.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>