让intel x550在新的驱动下可以协商出2.5G和5G
还没详细测试，慎用
====================================================================== https://downloadmirror.intel.com/732258/readme.txt
By default, devices based on the Intel(R) Ethernet Controller x550 do not advertise 2.5 Gbps or 5 Gbps. To have your device advertise these speeds, use the following:
# ethtool -s advertise N
Where N is a combination of the following.
100baseTFull 0x008
1000baseTFull 0x020
2500baseTFull 0x800000000000
5000baseTFull 0x1000000000000
10000baseTFull 0x1000
For example, to turn on all modes:
# ethtool -s advertise 0x1800000001028