trace: select TIMER_EARLY to avoid infinite recursion

When tracing functions is enabled this adds calls to
__cyg_profile_func_enter() and __cyg_profile_func_exit() to the traced
functions.

__cyg_profile_func_enter() and __cyg_profile_func_exit() invoke
timer_get_us() to record the entry and exit time.

initr_dm() will make gd->dm_root = NULL and gd->timer = NULL, so
timer_get_us() -> get_ticks() -> dm_timer_init() will lead to an
indefinite recursion.

So select TIMER_EARLY when tracing got enabled.

Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Rick Chen <rick@andestech.com>