[ALPS08836730] disp: fix discrete report abnormal fps

[Description]
fix discrete report abnormal fps.

[Test]
build pass.
customer test pass.

MTK-Commit-Id: 3abafca2a8ab33d656ef2624e3fc570db7687d0d

Signed-off-by: randy lin <randy.lin@mediatek.com>
CR-Id: ALPS08836730
Feature: display_mobile
Change-Id: I30e962f6647af349154f5a4c595be8d5a48dcf94