6e3hc3: change TE pulse width in fixed TE mode

We get weird TE timing during refresh rate transition. According
information from internal teams, it happens while switching between
fixed TE and changeable TE mode. Adjust suitable `WIDTH SET` in fixed
TE mode to avoid this problem.

Bug: 187044917
Test: refresh rate switch, chrome, facebook, youtube
Test: play video (rotation + downscale), camera
Signed-off-by: Midas Chien <midaschieh@google.com>
Change-Id: I9ae37415aa76ed7f1763ff0d2fabc56b0ab9ba05