projects/Cuboxi/linux: cleanup kernel config

Signed-off-by: Stephan Raue <stephan@openelec.tv>
libcec: cleanup

Signed-off-by: Stephan Raue <stephan@openelec.tv>
projects/*/linux: enable 'CONFIG_DRM_LOAD_EDID_FIRMWARE'

Signed-off-by: Stephan Raue <stephan@openelec.tv>