mtplot: option to render all points with a single pressure

This is useful for looking at linearity when pressure flucturates a
lot.

BUG=chromium:358292
TEST=tested on Pixel

Change-Id: I0f32b82de297623c5d7deb043f74da755d8fa7f6
Reviewed-on: https://chromium-review.googlesource.com/192370
Reviewed-by: Yufeng Shen <miletus@chromium.org>
Commit-Queue: Andrew de los Reyes <adlr@chromium.org>
Tested-by: Andrew de los Reyes <adlr@chromium.org>
1 file changed