netmiko ssh_autodetect support for aruba_aoscx

[sungajjar]

I tested ssh_autodetect support for aruba_aoscx by adding below code and it works for Aruba CX switches

"aruba_aoscx": {
    "cmd": "show version",
    "search_patterns": ["ArubaOS-CX"],
    "priority": 99,
    "dispatch": "_autodetect_std",
}