hdctools: Add overlay for sarien board

Add a simple overlay for the sarien board.

Turn off JTAG vref sel0/sel1 and UART1_EN so the EC can power
up from G3.

TEST=sudo servod -b sarien, apply power to sarien board and see it boot

Change-Id: Ib3850ac93cd1bf37577ff420102d2b29b578c999
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1266022
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
2 files changed