Add support for eCSA

Add support for eCSA

Extended channel switch provides an ability to switch between operating
classes and is required for P2P Devices by the P2P specification when
switching in 5 GHz.

When the operating class is provided for channel switch, the AP/P2P GO
will use eCSA IE in addition to the regular CSA IE both on 2.4 GHz and 5
GHz bands.

Transitions between different hw_modes are not supported.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>