Append security base config to BoardConfig, like:
REALDIR=`dirname $(readlink -f ${BASH_SOURCE[0]})`
source ${REALDIR}/BoardConfig-security-base.mk
MUST add it at the end of BoardConfig, so that
the parameter can't be recovered.
Signed-off-by: Zain Wang <wzz@rock-chips.com>
Change-Id: Ibdd183c1d37cd885587bb44e6c2b98ab9cba2cff
