[media] media: Driver for Toshiba et8ek8 5MP sensor

Add driver for et8ek8 sensor, found in Nokia N900 main camera. Can be
used for taking photos in 2.5MP resolution with fcam-dev.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>