configs: qcs615/qcs9100: Enable watchdog autostart

Enable watchdog autostart for QCS615 and QCS9100 platforms to ensure
the watchdog timer is automatically started during U-Boot
initialization.

Signed-off-by: Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>
Link: https://patch.msgid.link/20260526-wdt-v1-1-8236040fe56a@oss.qualcomm.com
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>