reproduce (this is a W=1 build):
        # https://github.com/Freescale/linux-fslc/commit/66c0769b6ca8d3397c85672c9bc1ac97ff3004ff
        git remote add freescale-fslc https://github.com/Freescale/linux-fslc
        git fetch --no-tags freescale-fslc 6.6-2.0.x-imx
        git checkout 66c0769b6ca8d3397c85672c9bc1ac97ff3004ff
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/clk/imx/ drivers/firmware/imx/ drivers/i2c/busses/ drivers/input/touchscreen/ drivers/mailbox/ drivers/mtd/spi-nor/ drivers/phy/freescale/ drivers/pinctrl/freescale/ drivers/rpmsg/