google/celes: add new board as variant of cyan baseboard

Add support for google/celes (Samsung Chromebook 3) as
a variant of the cyan Braswell baseboard.

- Add board-specific code as the new celes variant
- Add new trackpad I2C device to the baseboard for potential
reuse by other variants

Sourced from Chromium branch firmware-celes-7287.92.B,
commit 9f0760a: Revert "Revert "soc/intel/braswell: Populate NVS SCC BAR1""

Change-Id: Id52d3c523bae7745b3dc04da012ab65c1fb37887
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/21572
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
12 files changed