Add a generic device that should work on x86_64 ChromeOS devices. This
is mostly a copy of tablet-x64uefi, with ChromeOS-specific stuff from
google-kevin. Keeps the UEFI parts so that it can still be booted with
alternative firmware (i.e. MrChromebox's RW_LEGACY builds). Lightly
tested on a Lenovo IdeaPad 3 Chromebook 11IGL05 (codename "Lick").
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
