We don't need an API specially for non-watchdog since sha1_csum_wd supports it by disabling CONFIG_HW_WATCHDOG and CONFIG_WATCHDOG. Set 0x10000 as default chunk size for SHA1. Signed-off-by: Raymond Mao <raymond.mao@linaro.org> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>