device-fsl

MA-16072 fix error in setting rbindex in FIT&Container

now uboot is build independently, "BOOTLOADER_RBINDEX" should be moved
to "UbootKernelBoardConfig.mk" so it can be accessed in "uboot.mk"

make "$(UBOOTENVSH)" as a phony target, so it can be updated every time
when build images. the ubootenv.sh is moved to "$(UBOOT_OUT)" directory
from "/tmp" to avoid potential affect on others use the same server to
build images.

default "/bin/sh" used by "make" does not support "source" command,
replace it with "."

after the rollback index properly set, dual bootloader with trusty on
evk_8mm can now boot up.

Change-Id: Iebccdf1657d5297298703e58f68c074edc5c925a
Signed-off-by: faqiang.zhu <faqiang.zhu@nxp.com>
Reviewed-on: http://androidsource.ap.freescale.net/project/10786
Reviewed-by: ji.luo <ji.luo@nxp.com>