arch: arc: change to CONFIG_INIT_ARCH_HW_AT_BOOT

align kconfig option CONFIG_ARC_CUSTOM_INIT to
CONFIG_INIT_ARCH_HW_AT_BOOT. Remove unused CONFIG_ARC_CUSTOM_INIT in
kconfig.

Signed-off-by: Yuguo Zou <yuguo.zou@synopsys.com>
3 files changed