media: uvcvideo: Limit power line control for Acer EasyCamera

The device does not implement the power line control correctly. Add a
corresponding control mapping override.

Bus 001 Device 003: ID 5986:1172 Acer, Inc EasyCamera
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0x5986 Acer, Inc
  idProduct          0x1172
  bcdDevice           56.04
  iManufacturer           3 Bison
  iProduct                1 EasyCamera
  iSerial                 2
  bNumConfigurations      1

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>