hwmon: qti_amoled_ecm: Fix initial value for ECM_WRITE_TO_SDAM

Whenever ECM is enabled by the user, some SDAM registers are
initialized for the proper operation. Change the initial value
for ECM_WRITE_TO_SDAM as per the hardware recommendation.

Change-Id: I7a414bb83640178055f3c5a463daa6328aaef69c
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>