ENGR00134110 Add kernel&bootloader image build into JB build system

Add Freescale bootloader target and kernel target with the
arm-eabi-4.6 toolchain

Change-Id: Ic536ca863bf9914cc90e9ab7866c8a01a7881e20
Signed-off-by: guoyin.chen <guoyin.chen@freescale.com>
build: update imx kernel path

Signed-off-by: Humberto Borba <humberos@gmail.com>