In order to correctly convert YUV color space to RGB, we have to know
color encoding and range.

Introduce these two properties using helper method.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190713120346.30349-2-jernej.skrabec@siol.net