libchromeos: Remove touchscreen calibration workaround for rush_ryu This is no longer needed in the latest version of device. cherry-picked from https://chromium-review.googlesource.com/#/c/239261/ BUG=chrome-os-partner:32041 TEST=manual on rush_ryu Change-Id: I70079bdc8f65ee9e6401a3c2839ab38ea5458fcd Reviewed-on: https://chromium-review.googlesource.com/239941 Reviewed-by: Dan Erat <[email protected]> Commit-Queue: Yufeng Shen <[email protected]> Tested-by: Yufeng Shen <[email protected]>