conman:  Fake WPACtrl support for Frenzy.

This creates a FrenzyWPACtrl class that uses wifi_files and QCSAPI to
emulate WPACtrl.

Refactored interface.Wifi tests a bit so that the same test code could
be used for interface.Wifi and interface.FrenzyWifi.

Change-Id: I5d2befa387ede9a62fc1b70f69c8f655ae4b9dd2
3 files changed