MAKEALL: fix get_target_arch() to adjust to '-' in Status field

[u-boot] / configs / cm_fx6_defconfig

CONFIG_SPL=y
CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/imx-common/spl_sd.cfg,MX6QDL,SPL"
CONFIG_ARM=y
CONFIG_TARGET_CM_FX6=y
CONFIG_DM=y
CONFIG_DM_GPIO=y
CONFIG_DM_SERIAL=y