e1000e: Count CRC in Tx statistics

The datasheet 8.19.29 "Good Packets Transmitted Count - GPTC (0x04080;
RC)" says:
> This register counts the number of good (no errors) packets
> transmitted. A good transmit packet is considered one that is 64 or
> more bytes in length (from <Destination Address> through <CRC>,
> inclusively) in length.

It also says similar for the other Tx statistics registers. Add the
number of bytes for CRC to those registers.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

hw/net/e1000e_core.c

@@ -691,7 +691,7 @@ e1000e_on_tx_done_update_stats(E1000ECore *core, struct NetTxPkt *tx_pkt)
     static const int PTCregs[6] = { PTC64, PTC127, PTC255, PTC511,
                                     PTC1023, PTC1522 };
 
-    size_t tot_len = net_tx_pkt_get_total_len(tx_pkt);
+    size_t tot_len = net_tx_pkt_get_total_len(tx_pkt) + 4;
 
     e1000x_increase_size_stats(core->mac, PTCregs, tot_len);
     e1000x_inc_reg_if_not_full(core->mac, TPT);