SystemUI: enable equalizer for Wifi display

While the EQ doesn't work while using the Chromecast, using Wireless
display (miracast) still allows for control of the EQ since it's
streaming from the device.

Change-Id: I7322429b39438e66c013456b6f8a3242e333d93a
Signed-off-by: Roman Birg <roman@cyngn.com>