Support for packets bigger than 1504 in vde_switch

Hello,

From our testing, it seems that packets bigger than 1504 are dropped by vde_switch.
Simply updating the size of the data in src/vde_switch/port.h to a higher value seems to fix the issue (we put 16384 ourselves instead of 1504).

Before:

root@dut:~# ping 1.1.1.1 -s 1476
PING 1.1.1.1 (1.1.1.1) 1476(1504) bytes of data.
1484 bytes from 1.1.1.1: icmp_seq=1 ttl=64 time=1.44 ms
^C
--- 1.1.1.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.447/1.447/1.447/0.000 ms
root@dut:~# ping 1.1.1.1 -s 1478
PING 1.1.1.1 (1.1.1.1) 1478(1506) bytes of data.
^C
--- 1.1.1.1 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

After the patch, packets are received on the other side.

Could you raise the value, or do you want me to contribute a patch with a higher value?
If I were to contribute, should the value in src/vde_vxlan/vxlan.h be updated as well?

I attached the patch for reference:
0001-add-support-for-jumbo.patch.txt

Regards,
Samuel

Start in src/vde_switch/port.h, where the packet data size is limited to 1504, and compare the related value in src/vde_vxlan/vxlan.h. Reproduce the boundary behavior with the ping commands from the issue, then verify that packets larger than 1504 are accepted and the relevant size limits remain consistent.