[media] em28xx: add support for the SpeedLink Vicious And Devine Laplace webcams

[media] em28xx: add support for the SpeedLink Vicious And Devine Laplace webcams

The SpeedLink Vicious And Devine Laplace webcam is using an EM2765 bridge and
an OV2640 sensor. It has a built-in microphone (USB standard device class)
and provides 3 buttons (snapshot, illumination, mute) and 2 LEDs (capturing/mute
and illumination/flash). It is also equipped with an eeprom.
The device is available in two colors: white (1ae7:9003) and black (1ae7:9004).
For further details see http://linuxtv.org/wiki/index.php/VAD_Laplace.
Please note the following limitations that need to be addressed later:
- resolution limited to 640x480 (sensor supports 1600x1200)
- picture quality needs to be improved
- AV-mute button doesn't work yet

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>