platform/chrome: cros_ec_lpc - Add support for Google Pixel 2

platform/chrome: cros_ec_lpc - Add support for Google Pixel 2

Since the verion of ACPI in Google BIOS does not enumerate the devices
in the LPC bus, the cros_ec_lpc driver resorts to DMI data to check if
a system is supported by the driver and autoload if built as a module.

Add information about the Google Pixel 2 to the DMI device table.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Olof Johansson <olof@lixom.net>