sandbox: Enable the early timer

Enable this so that tracing works with sandbox.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

configs/sandbox_defconfig

@@ -68,6 +68,7 @@ CONFIG_SOUND=y
 CONFIG_SOUND_SANDBOX=y
 CONFIG_SANDBOX_SPI=y
 CONFIG_TIMER=y
+CONFIG_TIMER_EARLY=y
 CONFIG_SANDBOX_TIMER=y
 CONFIG_TPM_TIS_SANDBOX=y
 CONFIG_USB=y