drm/komeda: Computing image enhancer internally

Enable image enhancer when the input data flow is 2x+ upscaling.

Signed-off-by: james qian wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190708070000.4945-1-james.qian.wang@arm.com