i700_evk: remove selinux as permissive and change /dev/dri/card0 ownerships/rights
SWiftshader cannot be executed properly with SELinux as enforcing.
device/mediatek/common/graphics/soft/BoardConfig.mk will add androidboot.selinux=permissive to the kernel command line.
It doesn't need to be set in boards project anymore.
It only concerns devices which use SWiftshader.