config: 9625: Enable VADC threshold monitoring

ADC_TM is used by VADC clients to set thresholds and
receive notifications. Clients include thermistors for
temperature notification and battery clients such as
vbatt notification.

Change-Id: I309a6532b2fa6109e2798f71cd053e7c72ec8c44
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>