msm: mdss: Disable ECG feature for all chipsets

Disbale ECG feature for all chipsets by default, for command
mode panels when the FPS is less than 30, NOC errors are seen
when some MDP registers are accessed after clocks are turned off
from mdss driver.

Change-Id: Ic90e995d1729411c0b784edab3893ae96b78320a
Signed-off-by: Raghavendra Ambadas <rambad@codeaurora.org>