Adds OPTEE_OS_HEADER_V2_BIN, OPTEE_OS_PAGER_V2_BIN and
OPTEE_OS_PAGEABLE_V2_BIN which are used instead of OPTEE_OS_BIN when
using upstream ARM-TF image 2 loading.

Acked-by: Victor Chong <victor.chong@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>