defconfig: enable boot time marker driver for sa515 target

Enable this driver for start-up time measurement.

Change-Id: Ibd84a4d2f7c071d34ace75edf4d326218230e848
Acked-by: Abhishek Chauhan <abchauha@qti.qualcomm.com>
Signed-off-by: Sunil Paidimarri <hisunil@codeaurora.org>