CHROMIUM: Platform: x86: chromeos_laptop - Change identifiers for Pixel

CHROMIUM: Platform: x86: chromeos_laptop - Change identifiers for Pixel

Change the names of the setup functions for Pixel's atmel
touchscreen and touchpad.

Also, enable the name search for "touchscreen" for the atmel 1664s
irq number in dmi data.

Finally, change some of the Chromebook Pixel related identifiers
in chromeos_laptop_dmi_table.

Signed-off-by: Benson Leung <bleung@chromium.org>
BUG=chrome-os-partner:17951
TEST=Builds clean. Touchscreen, touchpad, and keyboard backlight all work.

Change-Id: I6945c5d64aea6943ea8468f761a8213eb4d4b498
Reviewed-on: https://gerrit.chromium.org/gerrit/43727
Reviewed-by: Puneet Kumar <puneetster@chromium.org>
Tested-by: Benson Leung <bleung@chromium.org>
Commit-Queue: Benson Leung <bleung@chromium.org>